Method and apparatus for pricing securities

• US 8,359,252 B2
• Filed: 12/23/2004
• Issued: 01/22/2013
• Est. Priority Date: 12/24/2003
• Status: Expired due to Fees

• Current Assignee: John Michael Redmayne
• Original Assignee: John Michael Redmayne
• Inventors: Redmayne, John Michael
• Primary Examiner(s): Bartley, Kenneth
• Application Number:
  US10/584,826
• Publication Number:
  US 20090106133A1
• Time in Patent Office: 2,952 Days
• Field of Search: 705/35, 705/36.R, 705/38
• US Class Current: 705/35
• CPC Class Codes: G06Q 30/0283 Price estimation or determination
• CPC Class Codes: G06Q 40/00 Finance; Insurance; Tax strategies; Processing of corporate or income taxes
• CPC Class Codes: G06Q 40/03 Credit; Loans; Processing thereof
• CPC Class Codes: G06Q 40/06 Asset management; Financial planning or analysis

Abstract

The invention provides computer-implemented techniques and systems for parsimoniously modelling the price or value, expected rate of return or other relevant characteristics of securities issued by, or referenced to, firms (or other assets) by incorporating risk premia such that a range of different securities can be evaluated within a single, unified and coherent framework, thereby leading to significant reduction in the computing resources otherwise required.

Claims

1. A computer implemented method for relating a price or value of each of a plurality of securities associated with an underlying asset, a rate of return on each of the plurality of securities, and risk attributes of each of the plurality of securities, the method comprising the steps of:

receiving, by one or more computers, data on a plurality of securities;

determining, by the one or more computers, a risk premium incorporated in the rate of return for each of the plurality of securities, wherein the risk premium for each of the plurality of securities comprises a difference between the rate of return for that security and a risk free rate of return;

determining, by the one or more computers, one or more priced risk factor premiums, wherein each of the priced risk factor premiums is a price per unit of risk for a priced risk factor multiplied by a measure of the security'"'"'s exposure to that priced risk factor, and wherein the risk premium for each of the securities is the priced risk factor premium, or, when the priced risk factor premium is part of a plurality of priced risk factor premiums, a sum of priced risk factor premiums;

wherein one of the priced risk factor premiums is in respect of volatility measured over a discrete time and wherein a price per unit of volatility is the same for two or more of each of the plurality of securities;

creating, by the one or more computers, a model for execution by the one or more computers, wherein the model calculates at least one value based on the determined priced risk factor premium; and

storing, by the one or more computers, the determined priced risk factor premiums for the plurality of securities, the calculated model and the at least one value.

2. The computer implemented method of claim 1, wherein at least one of said plurality of securities is a debt-type instrument, and further comprising analysing a yield spread associated with the debt-type instrument and identifying a default loss component and a risk premium component of said yield spread.

3. The computer implemented method of claim 1, further comprising fitting the model.

4. The computer implemented method of claim 3, further comprising providing as output to a user parameters of the fitted model.

5. The computer implemented method of claim 1, wherein the rate of return for a security of the plurality of securities is analysed utilising an estimate of an expected default loss of another security of the plurality of securities that is of a debt-type (security j), the method further comprising the steps of:

determining the rate of return on security j (r_j) by reference to a promised yield on said security (y_j) and the expected default loss (EDL_j) on said security where;

r_j=y_j−

EDL_j

calculating the risk premium for said security j as equal to r_j−

r, where r is the risk free rate of return;

calculating the exposure of each security to each priced risk factor (m);

calculating the price per unit of risk (λ

_m) for each priced risk factor (m), wherein each λ

_m is the same for two or more securities issued by, or referenced to, a firm and wherein a sum of a product of the exposures for security j and the prices per unit of risk equals the risk premium for security j, and for any other security for which an estimate of its risk premium is available;

designating that one of the priced risk factors relates to the volatility, estimated over a discrete time period, of the rate of return on securities and is specific to securities issued by, or referenced to, the firm;

calculating an excess rate of return for all other securities, other than j, based at least partly on their exposure to each priced risk factor and the price per unit of risk for each risk factor;

fitting the model; and

providing as output to a user parameters to the user from the fitted model.

6. The computer implemented method of claim 5, wherein the only priced risk factor comprises a volatility of returns and is implemented by:

designating a relationship between a firm specific price of volatility risk (λ

_σ

), the rate of return for j (r_j.), the volatility of returns (σ

_j) and the risk free rate of return (r) as;

7. The computer implemented method of claim 1, wherein one or more of the plurality of securities is an option, the method further comprising the steps of:

specifying a real world distribution process that returns on an underlying asset are expected to follow;

receiving pricing data on the option;

receiving adjustments for at least one factor specified by a user;

calculating an expected real world probability of the option being exercised based on the real world distribution process and the option'"'"'s pricing features;

calculating an expected mean, an expected standard deviation and other higher moments of interest of the option, at a time the option is expected to be exercised;

using the expected mean value of the option, at the time the option is expected to be exercised, and the option'"'"'s pricing data to calculate an expected real world pay off from the option;

discounting back to present value at a chosen evaluation date the expected real world pay off from the option using a risk adjusted discount rate, where said risk adjusted discount rate includes a priced risk factor premium for the expected standard deviation measured over discrete time of the expected real world pay off, for such other higher moments of interest to the user and adjustments for the at least one factor specified by the user, wherein the price per unit of risk, for each risk factor, is equated for two or more assets or securities selected from the option being discounted, the underlying asset and any other securities of interest referenced thereto; and

providing as output to the user parameters from a fitted model.

8. The computer implemented method of claim 7, further comprising the step of using the calculated values for the rate of return, standard deviation, other higher moments of interest and any other factors specified by the user for the asset as input to price or value other options contingent on the same or similar assets.

9. The computer implemented method of claim 7, wherein the real world distribution process that the returns on the underlying asset are expected to follow is modelled as a specified statistical distribution, wherein the expected mean, the expected standard deviation and other higher moments of interest of the portions of that distribution relevant to the one or more plurality of securities are estimated using closed-form type formula solutions or numerical approximations appropriate for the specified distribution process.

10. The computer implemented method of claim 9, wherein the real world distribution process that returns on the underlying asset are expected to follow is a normal distribution.

11. The computer implemented method of claim 1, wherein a user applies an option-theoretic model of a firm, the method further comprising the steps of:

determining a plurality of input parameters, the parameters including a risk premium in the rate of return for each security issued by, or referenced to, the firm;

defining relationships between said parameters;

fitting the model; and

providing as output to a user parameters from the fitted model.

12. The computer implemented method of claim 11, further comprising the steps of:

receiving pricing data on the securities;

receiving adjustments for at least one factor specified by a user;

specifying a real world distribution process that returns on total assets of the firm are expected to follow;

specifying a default point representing a value of the total assets of the firm at which the firm is expected to default;

calculating an expected real world probability of the default point being met;

calculating an expected mean, an expected standard deviation and other higher moments of interest of the securities, based on a real world distribution process modelled for the total assets of the firm and the default point, at the time horizon of interest;

using the expected mean value of the securities, at the time horizon of interest, and the securities'"'"' pricing data to calculate an expected real world pay off of the securities, at the time horizon of interest;

discounting back to present value at a chosen evaluation date the expected pay offs of each security using a risk adjusted discount rate, where said risk adjusted discount rate includes a priced risk factor premium for the expected standard deviation of the expected pay off from the security, for such other higher moments of interest to the user and adjustments for the at least one factor specified by the user, wherein the price per unit of risk, for each such risk factor, is equated for two or more securities issued by, or referenced to, the firm;

fitting the model; and

providing as output to a user parameters from the fitted model.

13. The computer implemented method of claim 12, wherein the real world distribution process that the returns on the total assets of the firm are expected to follow is modelled as a specified statistical distribution, wherein the expected mean, the expected standard deviation and other higher moments of interest of the portions of that distribution relevant to a security of the plurality of securities are estimated using closed-form type formula solutions or numerical approximations appropriate for the specified statistical distribution process.

14. The computer implemented method of claim 13, wherein the real world distribution process that the returns on total assets of the firm are expected to follow is a normal distribution.

15. The computer implemented method of claim 14, wherein the firm has, or is treated as having, only a single class of zero coupon debt on issue and further comprising the steps of:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of the total assets of the firm at time n (V_n), wherein the value of the total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a promised yield on the firm'"'"'s debt, per annum (y),

a risk free rate of return, per annum (r),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

a standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on the firm'"'"'s equity, per annum (σ

_S);

calculating values for d₁ and d₂, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

d₂=d₁−

σ

_S√

{square root over (T)};

calculating values for;

16. The computer implemented method of claim 11 further comprising the steps of:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a rate of return on the firm'"'"'s equity, per annum (r_S),

a rate of return on the firm'"'"'s debt, per annum (r_B),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

calculating a value for d₁, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)})

calculating a value for an instantaneous standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B), using the formula;

17. The computer implemented method of claim 11 further comprising the steps of:

receiving user selection of one or more of the following parameters, to be calculated over discrete time, for calibration with the model;

a standard deviation of rates of return on a firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on a firm'"'"'s equity, per annum (σ

_S),

a correlation of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity (ρ

_BS),

a correlation of rates of return on total assets of the firm and on the firm'"'"'s debt (ρ

_VS),

a correlation of rates of return on the total assets of the firm and on the firm'"'"'s equity (ρ

_VS),

a covariance of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity, per annum (σ

_BS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s debt, per annum (σ

_VB),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s equity, per annum (σ

_VS),

calculating values for the one or more parameters so selected using one or more of the following formula;

18. The computer implemented method of claim 11, further comprising the steps of:

defining additional multi-variate equations representing relationships between variables, which comprise some or all of the inputs to and/or outputs from the model; and

solving all of the multi-variate equations and the model to calculate revised values for the variables in the multi-variate equations and the model.

19. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises a statistical moment of one of the securities of the plurality of securities.

20. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises a correlation between the returns of a pair of securities of the plurality of securities.

21. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises a covariance between returns of a pair of securities of the plurality of securities.

22. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises a correlation between returns of a security of the plurality of securities and returns of total assets of the firm.

23. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises a covariance between returns of a security of the plurality of securities and returns of total assets of the firm.

24. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises an expected probability of default.

25. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises an expected loss given default on a debt-type of the plurality of securities.

26. The computer implemented method of claim 18, wherein at least one of the variables included in one or more additional multi-variate equations comprises an expected default loss on a debt-type security of the plurality of securities.

27. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is a statistical moment of returns of one of the plurality of securities.

28. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is a correlation between the returns of a pair of the plurality of securities.

29. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is a covariance between returns of a pair of the plurality of securities.

30. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is a correlation between returns of one of the plurality of securities and returns of total assets of the firm.

31. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is a covariance between returns of one of the plurality of securities and returns of total assets of the firm.

32. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is an expected probability of default.

33. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is an expected loss given default on a debt-type security of the plurality of securities.

34. The computer implemented method of claim 11, further comprising the steps of generating one or more parameters from the model and solving the model so that the parameters equal values specified by the user, where one of the parameters is an expected default loss on a debt-type security of the plurality of securities.

35. A computer implemented method for applying an option-theoretic model of a firm comprising the steps of:

receiving, by one or more computers, one or more risk parameters, wherein the one or more risk parameters are related to the firm;

specifying, by the one or more computers, one or more input parameters, wherein the one or more input parameters are to be used in the option-theoretic model of the firm;

defining, by the one or more computers, mathematical relationships between the input parameters, wherein the mathematical relationships are a set of one or more equations for execution by the one or more computers;

creating, by the one or more computers, the option-theoretic model of the firm, based on the defined mathematical relationships;

receiving, by the one or more computers, at least one value for each of the one or more input parameters;

calculating, by the one or more computers, using the option-theoretic model, an estimated value for one or more of the risk parameters, measured over a discrete time period;

re-calculating, by the one or more computers, using the option-theoretic model, a solution, the solution comprising at least one estimated value for each of the one or more input parameters that a user allows to vary from the at least one received value, such that the at least one estimated risk parameter value from the model equals the at least one risk parameter value received by the one or more computers; and

storing, by the one or more computers, the calculated option-theoretic model and the at least one estimated value of each of the one or more input parameters that the user allows to vary.

36. The computer implemented method of claim 35, wherein one of the risk parameters is a statistical moment of returns of one or more securities issued by, or referenced to, the firm.

37. The computer implemented method of claim 35, wherein one of the risk parameters is a correlation between returns of a pair of securities issued by, or referenced to, the firm.

38. The computer implemented method of claim 35, wherein one of the risk parameters is a covariance between returns of a pair of securities issued by, or referenced to, the firm.

39. The computer implemented method of claim 35, wherein one of the risk parameters is a correlation between returns of a security issued by, or referenced to, the firm and returns of total assets of the firm.

40. The computer implemented method of claim 35, wherein one of the risk parameters is a covariance between returns of a security issued by, or referenced to, the firm and returns of total assets of the firm.

41. The computer implemented method of claim 35 further comprising the steps of:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a rate of return on the firm'"'"'s equity, per annum (r_S),

a rate of return on the firm'"'"'s debt, per annum (r_B),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

calculating a value for d₁, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

calculating a value for an instantaneous standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B), using the formula;

42. The computer implemented method of claim 35 further comprising the steps of:

receiving user selection of one or more of the following parameters, to be calculated over discrete time, for calibration with the model;

a standard deviation of rates of return on a firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on a firm'"'"'s equity, per annum (σ

_S),

a correlation of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity (ρ

_BS),

a correlation of rates of return on total assets of the firm and on the firm'"'"'s debt (ρ

_VS),

a correlation of rates of return on the total assets of the firm and on the firm'"'"'s equity (ρ

_VS),

a covariance of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity, per annum (σ

_VS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s debt, per annum (σ

_VS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s equity, per annum (σ

_VS),

calculating values for the one or more parameters so selected using one or more of the following formula;

43. A system for relating a price or value of a plurality of securities associated with an underlying asset, a rate of return on each of the plurality of securities, and risk attributes of each of the plurality of securities, the system comprising:

at least one processor; and

at least one computer-readable memory communicatively coupled to the at least one processor, the memory storing processor-executable instructions that, when executed by the at least one processor, causes the system to perform operations comprising;

receiving data on a plurality of securities;

determining a risk premium incorporated in the rate of return for each of the plurality of securities, wherein the risk premium for each of the plurality of securities comprises a difference between the rate of return for that security and a risk free rate of return;

determining one or more priced risk factor premiums, wherein each of the priced risk factor premiums is a price per unit of risk for a priced risk factor multiplied by a measure of the security'"'"'s exposure to that priced risk factor and wherein the risk premium for each of the securities is the priced risk factor premium, or, when the priced risk factor premium is part of a plurality of priced risk factor premiums, a sum of priced risk factor premiums; and

wherein one of the priced risk factor premiums is in respect of volatility measured over a discrete time and wherein a price per unit of volatility is the same for two or more of each of the plurality of securities;

creating a model, wherein the model calculates at least one value based on the determined priced risk factor premium; and

storing the determined priced risk factor premiums for the plurality of securities, the calculated model and the at least one value.

44. The computer system of claim 43, wherein at least one of said plurality of securities is a debt-type instrument, and the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

analyzing a yield spread associated with the debt-type instrument and identify a default loss component and a risk premium component of said yield spread.

45. The computer system of claim 43, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

fitting the model.

46. The computer system of claim 45, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

providing as output to a user, via the user interface, parameters of the fitted model.

47. The computer system of claim 43, wherein an estimate of the expected default loss of another security that is of a debt-type (security j) issued by, or referenced to, the firm, is utilised in analysing a rate of return for a security (or securities) issued by, or referenced to, a firm, and wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

determining the rate of return on security j (r_j) by reference to a promised yield on said security (y) and the expected default loss (EDL) on said security where

r_j=y_j−

EDL_j;

calculating a risk premium for said security j as equal to r_j−

r, where r is the risk free rate of return;

calculating the exposure of each security to each priced risk factor (m);

calculating the price per unit of risk (λ

_m) for each priced risk factor (m), wherein each λ

_m is the same for two or more securities issued by, or referenced to, a firm and wherein a sum of a product of the exposures for security j and the prices per unit of risk equals the risk premium for security j, and for any other security for which an estimate of its risk premium is available;

designating that one of the priced risk factors relates to the volatility, estimated over a discrete time period, of the rate of return on securities and is specific to securities issued by, or referenced to, the firm;

calculating a risk premium for all of the other securities, other than j, based at least partly on their exposure to each priced risk factor and the price per unit of risk for each risk factor;

fitting the model; and

providing as output to a user parameters to the user from the fitted model.

48. The computer system of claim 47, wherein the priced risk factor analysed in the system comprises a volatility of returns, and wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising;

designating a relationship between a firm specific price of volatility risk (λ

_σ

), the rate of return for j (r_j), the volatility of returns (σ

_j) and the risk free rate of return (r) as;

49. The computer system of claim 43, wherein one or more of the plurality of securities being analysed by the system is an option, and wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

specifying a real world distribution process that returns on an underlying asset are expected to follow;

receiving pricing data on the option;

receiving adjustments for at least one factor specified by a user;

calculating an expected real world probability of the option being exercised based on the real world distribution process and the option'"'"'s features;

calculating an expected mean of the option, at a time the option is expected to be exercised;

calculating the standard deviation and other higher moments of interest of the option, at the time the option is expected to be exercised;

using the expected mean value of the option, at the time the option is expected to be exercised, and the option'"'"'s pricing data to calculate an expected real world pay off from the option;

discounting back to present value at a chosen evaluation date the expected real world pay off from the option using a risk adjusted discount rate, where said risk adjusted discount rate includes a priced risk factor premium for the expected standard deviation measured over discrete time of the expected real world pay off, for such other higher moments of interest to the user and adjustments for the at least one factor specified by the user, wherein the price per unit of risk, for each risk factor, is equated for two or more assets or securities selected from the options being discounted, the underlying asset and any other securities of interest referenced thereto; and

providing as output to the user parameters from a fitted model.

50. The computer system of claim 49, wherein the at least one-memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

using the estimated values for the rate of return, standard deviation, other higher moments of interest and any other factors specified by the user for the asset, derived as output from said claims, as input to price or value other options contingent on the same or similar assets.

51. The computer system of claim 49, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

modelling the real world distribution process that the returns on the underlying asset are expected to follow as a specified statistical distribution, wherein the mean, standard deviation and other higher moments of interest of the portions of that distribution relevant to a security are estimated using closed-form type formula solutions or numerical approximations appropriate for the specified statistical distribution process.

52. The computer system of claim 51, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

modelling the real world distribution process that the returns on the underlying asset are expected to follow as the normal distribution.

53. The computer system of claim 43, wherein the user applies an option-theoretic model of the firm, and wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

determining a plurality of input parameters, the parameters including a risk premium in the rate of return for each security issued by, or referenced to, the firm;

defining relationships between said parameters;

fitting the model; and

providing as output to a user parameters from the fitted model.

54. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

receiving pricing data on the securities issued by, or referenced to, the firm;

receiving adjustments for at least one factor specified by a user;

specifying a real world distribution process that returns on total assets of the firm are expected to follow;

specifying a default point representing a value of the total assets of the firm at which the firm is expected to default;

calculating an expected real world probability of the default point being met;

calculating an expected mean of the securities, based on a real world distribution process modelled for the total assets of the firm and the default point, at the time horizon of interest;

calculating a standard deviation and other higher moments of interest of the securities, based on a real world distribution process modelled for the total assets of the firm and the default point, at the time horizon of interest;

using the expected mean value of the securities, at the time horizon of interest, and the securities'"'"' pricing data to calculate an expected real world pay off of the securities, at the time horizon of interest;

discounting back to present value at a chosen evaluation date the expected pay offs of each security using a risk adjusted discount rate, where said risk adjusted discount rate includes a priced risk factor premium for the expected standard deviation of the expected pay off from the security, for such other higher moments of interest to the user and adjustments for the at least one factor specified by the user, wherein the price per unit of risk, for each such risk factor, is equated for two or more securities issued by, or referenced to, the firm;

fitting the model; and

providing as output to a user parameters from the fitted model.

55. The computer system of claim 54, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

modelling the real world distribution process that the returns on total assets of the firm are expected to follow as a specified statistical distribution, wherein the mean, standard deviation and other higher moments of interest of the portions of that distribution relevant to a security are estimated using closed-form type formula solutions or numerical approximations appropriate for the specified statistical distribution process.

56. The computer system of claim 55, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

modelling the real world distribution process that the returns on total assets of the firm are expected to follow as the normal distribution.

57. The computer system of claim 56, wherein the firm has only a single class of zero coupon debt on issue and the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of the total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a promised yield on the firm'"'"'s debt, per annum (y),

a risk free rate of return, per annum (r),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

a standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on the firm'"'"'s equity, per annum (σ

_S);

calculating values for d₁ and d₂, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

d₂=d₁−

σ

_V√

{square root over (T)};

calculating values for;

58. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

defining additional multi-variate equations representing relationships between variables, which comprise some or all of the inputs to and/or outputs in the claim; and

solving all of the multi-variate equations and the model used in the claim, to calculate revised values for the variables in the multi-variate equations and the model.

59. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations a statistical moment of one of the securities issued by, or referenced to the firm.

60. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the correlation between the returns of a pair of securities issued by, or referenced to, the firm.

61. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the covariance between the returns of a pair of securities issued by, or referenced to, the firm.

62. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the correlation between the returns of a security issued by, or referenced to, the firm and the returns of total assets of the firm.

63. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the covariance between the returns of a security issued by, or referenced to, the firm and the returns of total assets of the firm the total firm.

64. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the expected probability of default.

65. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the expected loss given default on a debt-type security issued by, or referenced to, the firm.

66. The computer system of claim 58, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

including as at least one of the variables in one or more additional multi-variate equations the expected default loss on a debt-type security issued by, or referenced to, the firm.

67. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is a statistical moment of the returns of one of the securities issued by, or referenced to, the firm.

69. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the covariance between the returns of a pair of securities issued by, or referenced to, the firm.

70. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the correlation between the returns of a security issued by, or referenced to, the firm and the returns of total assets of the firm.

71. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the covariance between the returns of a security issued by, or referenced to, the firm and the returns of total assets of the firm.

72. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the expected probability of default.

73. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the expected loss given default on a debt-type security issued by, or referenced to, the firm.

74. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the expected default loss on a debt-type security issued by, or referenced to, the firm.

75. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a promised yield on the firm'"'"'s debt, per annum (r_S),

a risk free rate of return, per annum (r_B),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

calculating a value for d₁, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

calculating a value for an instantaneous standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B), using the formula;

76. The computer system of claim 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

receiving user selection of one or more of the following parameters, to be calculated over discrete time, for calibration with the model;

a standard deviation of rates of return on a firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on a firm'"'"'s equity, per annum (σ

_S),

a correlation of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity (ρ

_BS),

a correlation of rates of return on total assets of the firm and on the firm'"'"'s debt (ρ

_VS),

a correlation of rates of return on the total assets of the firm and on the firm'"'"'s equity (ρ

_VB),

a covariance of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity, per annum (σ

_BS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s debt, per annum (σ

_VB),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s equity, per annum (σ

_VS),

calculating values for the one or more parameters so selected using one or more of the following formula;

68. The computer system of 53, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

generating one or more parameters from the model and solving the model so that the parameters equal values specified by a user, where one of the parameters is the correlation between the returns of a pair of securities issued by, or referenced to, the firm.

77. A system for applying an option-theoretic model of a firm, the system comprising:

at least one processor; and

at least one computer-readable memory communicatively coupled to the at least one processor, the memory storing processor-executable instructions that, when executed by the at least one processor, causes the system to perform operations comprising;

receiving one or more risk parameters, wherein the one or more risk parameters are related to the firm;

specifying one or more input parameters, wherein the one or more input parameters are to be used in the option-theoretic model of the firm;

defining mathematical relationships between the input parameters, wherein the mathematical relationships are a set of one or more equations for;

creating, the option-theoretic model of the firm, based on the defined mathematical relationships;

receiving at least one value for each of the one or more input parameters;

calculating using the option-theoretic model, an estimated value for one or more of the risk parameters, measured over a discrete time period;

re-calculating using the option-theoretic model, a solution, the solution comprising at least one estimated value for each of the one or more input parameters that a user allows to vary from the at least one received value, such that the at least one estimated risk parameter value from the model equals the at least one risk parameter value received; and

storing the calculated option-theoretic model and the at least one estimated value of each of the one or more input parameters that the user allows to vary.

78. The computer system of claim 77, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

using as one of the risk parameters a statistical moment of returns of one or more securities issued by, or referenced to, the firm.

79. The computer system of claim 77, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

using as one of the risk parameters a correlation between returns of a pair of securities issued by, or referenced to, the firm.

80. The computer system of claim 77, wherein the memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

using as one of the risk parameters a covariance between returns of a pair of securities issued by, or referenced to, the firm.

81. The computer system of claim 77, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

using as one of the risk parameters a correlation between returns of a security issued by, or referenced to, the firm and returns of total assets of the firm.

82. The computer system of claim 77, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

using as one of the risk parameters a covariance between returns of a security issued by, or referenced to, the firm and returns of the total assets of the firm.

83. The computer system of claim 77, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

receiving values for;

a value of the equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a rate of return on the firm'"'"'s equity, per annum (r_S),

a rate of return on the firm'"'"'s debt, per annum (r_B),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

calculating a value for d₁, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

calculating a value for an instantaneous standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B), using the formula;

84. The computer system of claim 77, wherein the at least one memory further bears processor-executable instructions that, when executed on the at least one processor, cause the at least one processor to perform operations comprising:

receiving user selection of one or more of the following parameters, to be calculated over discrete time, for calibration with the model;

a standard deviation of rates of return on a firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on a firm'"'"'s equity, per annum (σ

_S),

a correlation of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity (ρ

_BS),

a correlation of rates of return on total assets of the firm and on the firm'"'"'s debt (ρ

_VS)

a correlation of rates of return on the total assets of the firm and on the firm'"'"'s equity (ρ

_VS),

a covariance of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity, per annum (σ

_BS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s debt, per annum (σ

_VS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s equity, per annum (σ

_VS),

calculating values for the one or more parameters so selected using one or more of the following formula;

85. A non-transitory computer-readable medium for relating a price or value of a plurality of securities associated with an underlying asset, a rate of return on each of the plurality of securities, and risk attributes of each of the plurality of securities, storing computer-executable instructions that, upon execution by one or more computers, cause the one or more computers to perform operations comprising:

receiving data on a plurality of securities;

determining a risk premium incorporated in the rate of return for each of the plurality of securities, wherein the risk premium for each of the plurality of securities comprises a difference between the rate of return for that security and a risk free rate of return;

determining one or more priced risk factor premiums, wherein each of the priced risk factor premiums is a price per unit of risk for a priced risk factor multiplied by a measure of the security'"'"'s exposure to that priced risk factor and wherein the risk premium for each of the securities is the priced risk factor premium, or, when the priced risk factor premium is part of a plurality of priced risk factor premiums, a sum of priced risk factor premiums; and

wherein one of the priced risk factor premiums is in respect of volatility measured over a discrete time and wherein a price per unit of volatility is the same for two or more of each of the plurality of securities;

creating a model, wherein the model calculates at least one value based on the determined price risk factor premium; and

storing the determined price risk factor premiums for the plurality of securities, the calculated model and the at least one value.

86. The non-transitory computer-readable medium of claim 85, wherein at least one of said plurality of securities is a debt-type instrument, and further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

analysing a yield spread associated with the debt-type instrument and identifying a default loss component and a risk premium component of the yield spread.

87. The non-transitory computer-readable medium of claim 85, further-bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

fitting the model.

88. The non-transitory computer-readable medium of claim 87, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

outputting to a user parameters of the fitted model.

89. The non-transitory computer-readable medium of claim 85, further comprising computer-executable instructions for utilising an estimate of the expected default loss of another security that is of a debt-type (security j) issued by, or referenced to, the firm, in analysing the rate of return for a security (or securities) issued by, or referenced to, a firm, said computer-executable instructions, upon execution by the computer, causing the computer to perform operations comprising:

determining the a rate of return on security j (r_j) by reference to the promised yield on said security (y_j) and the expected default loss (EDL_j) on said security where;

r_j=y_j−

EDL_j

calculating the risk premium for said security j as equal to r_j−

r, where r is the a risk free rate of return;

calculating the exposure of each security to each priced risk factor (m);

calculating a price per unit of risk (λ

_m) for each priced risk factor (m), wherein each λ

_m is the same for two or more securities issued by, or referenced to, a firm and such that a sum of a product of the risk exposures for security j and the prices per unit of risk equals the risk premium for security j, and similarly for any other security for which an estimate of its risk premium is available;

designating that one of the priced risk factors relates to the volatility, estimated over a discrete time period, of the rate of return on securities and is specific to securities issued by, or referenced to, the firm;

calculating the risk premium of return for all of the other securities being analysed, other than j, based at least partly on their exposure to each priced risk factor and the price per unit of risk for each risk factor;

fitting the model; and

providing as output to a user parameters of interest to the user from the fitted model.

90. The non-transitory computer-readable medium of claim 89, wherein the only priced risk factor analysed in accordance with the computer-executable instructions is the volatility of returns and the computer-executable instructions, upon execution by the computer, cause the computer to perform operations comprising:

designating the relationship between the firm specific price of volatility risk (λ

_σ

), the rate of return for j (r_j), the volatility of returns for j (σ

_j) and the risk free rate of return (r) as;

91. The non-transitory computer-readable medium of claim 85, wherein one or more of the securities being analysed with the computer-executable instructions is an option, and further bearing computer executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

specifying the real world distribution process that the returns on the underlying asset are expected to follow;

receiving data on features of the option;

receiving adjustments for any factors specified by a user;

calculating the expected real world probability of the option being exercised based on the real world distribution process and the option'"'"'s features;

calculating the an expected mean, standard deviation and other higher moments of interest of the option, at the time the option is expected to be exercised;

using the expected mean value of the option, at the time the option is expected to be exercised, and the option'"'"'s features to calculate the expected real world pay off from the option;

discounting back to present value (as at the chosen evaluation date) the pay off from the option using a risk adjusted discount rate, where said risk adjusted discount rate includes a priced risk factor premium for the expected standard deviation (measured over discrete time) of the expected option pay off, for such other higher moments of interest to the user and adjustments for any other factors specified by a user, wherein the price per unit of risk, for each risk factor, is equated for two or more assets or securities selected from the options being evaluated, the underlying asset and any other securities of interest referenced thereto; and

providing as output to a user parameters of interest to the user from the fitted model.

92. The non-transitory computer-readable medium of claim 91, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

using the estimated values for the rate of return, standard deviation, other higher moments of interest and any other factors specified by a user for the asset, derived as output from said claims, as input to price or value other options contingent on the same or similar assets.

93. The non-transitory computer-readable medium of claim 91, wherein computer-executable instructions, upon execution by the computer, cause the computer to model the real world distribution process that the returns on the underlying asset are expected to follow as a specified statistical distribution, wherein the expected mean, the expected standard deviation and other higher moments of interest of the portions of that distribution relevant to the one or more of the plurality of securities are estimated using closed-form type formula solutions or numerical approximations appropriate for the specified distribution process.

94. The non-transitory computer-readable medium of claim 93, wherein the computer-executable instructions, upon execution by the computer, cause the computer to model the real world distribution process that returns on the underlying asset are expected to follow is a normal distribution.

95. The non-transitory computer-readable medium of claim 85, wherein a user applies an option-theoretic model of the firm and further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

determining a plurality of input parameters, the parameters including a risk premium in the rate of return for each security issued by, or referenced to, the firm;

defining relationships between said parameters;

fitting the model; and

providing as output to a user parameters of interest to the user from the fitted model.

96. The non-transitory computer-readable medium of claim 95, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

receiving pricing data on the securities;

receiving adjustments for at least one factor specified by a user;

specifying a real world distribution process that returns on total assets of the firm are expected to follow;

specifying a default point representing a value of the total assets of the firm at which the firm is expected to default;

calculating an expected real world probability of the default point being met;

calculating an expected mean, an expected standard deviation and other higher moments of interest of the securities, based on a real world distribution process modelled for the total assets of the firm and the default point, at the time horizon of interest;

using the expected mean value of the securities, at the time horizon of interest, and the securities'"'"' pricing data to calculate an expected real world pay off of the securities, at the time horizon of interest;

discounting back to present value at a chosen evaluation date the expected pay offs of each security using a risk adjusted discount rate, where said risk adjusted discount rate includes a priced risk factor premium for the expected standard deviation of the expected pay off from the security, for such other higher moments of interest to the user and adjustments for the at least one factor specified by the user, wherein the price per unit of risk, for each such risk factor, is equated for two or more securities issued by, or referenced to, the firm;

fitting the model; and

providing as output to a user parameters from the fitted model.

97. The non-transitory computer-readable medium of claim 96, wherein computer-executable instructions, upon execution by the computer, cause the computer to model the real world distribution process that returns on the total assets of the firm are expected to follow as a specified statistical distribution, wherein the expected mean, the expected standard deviation and other higher moments of interest of the portions of that distribution relevant to a security of the plurality of securities are estimated using closed-form type formula solutions or numerical approximations appropriate for the specified statistical distribution process.

98. The non-transitory computer-readable medium of claim 97, wherein the computer-executable instructions, upon execution by the computer, cause the computer to model the real world distribution process that returns on the total assets of the firm are expected to follow is a normal distribution.

99. The non-transitory computer-readable medium of claim 98, wherein the firm has, or is treated as having, only a single class of zero coupon debt on issue, and further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

receiving values for;

a value of an equity of a firm at time n (S_n),

a value of the total assets of the firm at time n (V_n), wherein the value of the total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a promised yield on the firm'"'"'s debt, per annum (y),

a risk free rate of return, per annum (r),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

a standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on the firm'"'"'s equity, per annum (σ

_S);

calculating values for d₁ and d₂, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

d₂=d₁−

σ

_V√

{square root over (T)};

calculating values for;

100. The non-transitory computer-readable medium of claim 95, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

defining additional multi-variate equations representing relationships between variables, which comprise some or all of the inputs to and/or outputs from the model; and

solving all of the multi-variate equations and the model to calculate revised values for the variables in the multi-variate equations and the model.

101. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations a statistical moment of one of the securities of the plurality of securities.

102. The non-transitory computer-readable medium in claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises a correlation between returns of a pair of securities of the plurality of securities.

103. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises a covariance between returns of a pair of securities of the plurality of securities.

104. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises a correlation between returns of a security of the plurality of securities and returns of total assets of the firm.

105. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises a covariance between returns of a security of the plurality of securities and returns of total assets of the firm.

106. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises an expected probability of default.

107. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises an expected loss given default on a debt-type security of the plurality of securities.

108. The non-transitory computer-readable medium of claim 100, wherein the computer-executable instructions include as at least one of the variables included in one or more additional multi-variate equations comprises an expected default loss on a debt-type security of the plurality of securities.

109. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is a statistical moment of returns of one of the plurality of securities.

110. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is a correlation between returns of a pair of the plurality of securities.

111. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is a covariance between returns of a pair of the plurality of securities.

112. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is a correlation between returns of one of the plurality of securities and returns of total assets of the firm.

113. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is a covariance between returns of one of the plurality of securities and returns of total assets of the firm.

114. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is an expected probability of default.

115. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is an expected loss given default on a debt-type security of the plurality of securities.

116. The non-transitory computer-readable medium of claim 95, wherein the computer-executable instructions, upon execution by the computer, cause the computer to generate one or more parameters from the model and solve the model so that the parameters equal values specified by the user, where one of the parameters is an expected default loss on a debt-type security of the plurality of securities.

117. The non-transitory computer-readable medium of claim 95, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a rate of return on the firm'"'"'s equity, per annum (r_S),

a rate of return on the firm'"'"'s debt, per annum (r_B),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

calculating a value for d₁, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

calculating a value for an instantaneous standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B), using the formula;

118. The non-transitory computer-readable medium of claim 95, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

receiving user selection of one or more of the following parameters, to be calculated over discrete time, for calibration with the model;

a standard deviation of rates of return on a firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on a firm'"'"'s equity, per annum (σ

_S),

a correlation of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity (ρ

_BS),

a correlation of rates of return on total assets of the firm and on the firm'"'"'s debt (ρ

_VB),

a correlation of rates of return on the total assets of the firm and on the firm'"'"'s equity (ρ

_VS),

a covariance of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity, per annum (σ

_BS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s debt, per annum (σ

_VB),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s equity, per annum (σ

_VS),

calculating values for the one or more parameters so selected using one or more of the following formula;

119. A non-transitory computer-readable medium for applying an option-theoretic model of a firm, storing computer-executable instructions that, upon execution by one or more computers, cause the one or more computers to perform operations comprising:

receiving one or more risk parameters, wherein the one or more risk parameters are related to the firm;

receiving one or more input parameters, wherein the one or more input parameters are to be used in the option-theoretic model of the firm;

receiving instructions on mathematical relationships between the input parameters, wherein the mathematical relationships are a set of one or more equations for execution by the one or more computers;

creating the option-theoretic model of the firm, based on the received instructions on mathematical relationships;

calculating, using the option-theoretic model, an estimated value for one or more of the risk parameters, measured over a discrete time period;

re-calculating, using the option-theoretic model, a solution, the solution comprising at least one estimated value for each of the one or more input parameters that a user allows to vary from the at least one received value, such that the at least one estimated risk parameter value from the model equals the at least one risk parameter value received by the one or more computers; and

storing the calculated option-theoretic model and the at least one estimated value of each of the one or more input parameters that the user allows to vary.

120. The non-transitory computer-readable medium of claim 119, wherein one of the risk parameters analysed by the computer-executable instructions is a statistical moment of returns of one or more securities issued by, or referenced to, the firm.

121. The non-transitory computer-readable medium of claim 119, wherein one of the risk parameters analysed by the computer-executable instructions is a correlation between returns of a pair of securities issued by, or referenced to, the firm.

122. The non-transitory computer-readable medium of claim 119, wherein one of the risk parameters analysed by the computer-executable instructions is a covariance between returns of a pair of securities issued by, or referenced to, the firm.

123. The non-transitory computer-readable medium of claim 119, wherein one of the risk parameters analysed by the computer-executable instructions is a correlation between returns of a security issued by, or referenced to, the firm and returns of total assets of the firm.

124. The non-transitory computer-readable medium of claim 119, wherein one of the risk parameters analysed by the computer-executable instructions is a covariance between returns of a security issued by, or referenced to, the firm and the returns of total assets of the firm.

125. The non-transitory computer-readable medium of claim 119, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

receiving values for;

a value of an equity of the firm at time n (S_n),

a value of total assets of the firm at time n (V_n), wherein the value of total assets of the firm is a sum of values of a firm'"'"'s debt (B_n) and equity (S_n),

a face value (X) of the firm'"'"'s debt (B), which is assumed to be a single zero-coupon bond, at maturity,

a user selected time horizon, in years (T),

a rate of return on the total assets of the firm, per annum (r_V),

a rate of return on the firm'"'"'s equity, per annum (r_S),

a rate of return on the firm'"'"'s debt, per annum (r_B),

a standard deviation of rates of return on the total assets of the firm, per annum (σ

_V),

calculating a value for d₁, wherein;

d₁=([ln(V₀/X)+r_VT]/σ

_V√

{square root over (T)})+(1/2)(σ

_V√

{square root over (T)}),

calculating a value for an instantaneous standard deviation of rates of return on the firm'"'"'s debt, per annum (σ

_B), using the formula;

126. The non-transitory computer-readable medium of claim 119, further bearing computer-executable instructions that, upon execution by the computer, cause the computer to perform operations comprising:

receiving user selection of one or more of the following parameters, to be calculated over discrete time, for calibration with the model;

a standard deviation of rates of return on a firm'"'"'s debt, per annum (σ

_B),

a standard deviation of rates of return on a firm'"'"'s equity, per annum (σ

_S),

a correlation of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity (ρ

_BS),

a correlation of rates of return on total assets of the firm and on the firm'"'"'s debt (ρ

_VB),

a correlation of rates of return on the total assets of the firm and on the firm'"'"'s equity (ρ

_VS),

a covariance of rates of return on the firm'"'"'s debt and on the firm'"'"'s equity, per annum (σ

_BS),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s debt, per annum (σ

_VB),

a covariance of rates of return on the total assets of the firm and on the firm'"'"'s equity, per annum (σ

_VS),

calculating values for the one or more parameters so selected using one or more of the following formula;