The AverageStrike function calculates the theoretical price, sensitivities, the implied volatility, and the implied strike value of a European arithmetic or geometric average strike option using either the Levy model for arithmetic or the Rubinstein model for geometric average price options. See Asian Options for a further explanation.
AverageStrike |
(OptionType, AverageType, ModelStatistic, Asset, TimeExpire, Volatility, InterestRate, YieldRate, ObserveFreq, MarketPrice, TimeFormat, InterestType, YieldType) |
Note: Optional arguments are shown in Italics. MarketPrice is not Optional for the Implied Calculations.
Argument |
Description |
OptionType |
Alphanumeric value indicating the type of option: •Call = 1 or "c" (case insensitive) •Put = 2 or "p" (case insensitive) |
AverageType |
Alphanumeric value indicating the Average type or model: •Geometric = 1 or "g" (case insensitive) •Arithmetic = 2 or "a" (case insensitive) |
ModelStatistic |
Numeric value indicating the type of function required for the return value: •Theoretical = 1 •Delta = 2 •Gamma = 3 •Theta = 4 •ImpliedVol = 5 •Vega = 6 •Rho = 7 •Psi = 8 •Lambda = 9 •StrikeSensitivity = 11 •ImpliedStrike = 13 |
Asset |
The price of the underlying asset. Must be > 0. |
TimeExpire |
Time, expressed in either Days or Years (depending on the TimeFormat value), until the options expiration. Must be > 0. |
Volatility |
Annualized volatility of the underlying security. Must be > 0. |
InterestRate |
Risk-free interest rate expressed as a percentage. This rate is interpreted as a continuously compounded rate unless otherwise specified in the InterestType argument. Must be > 0. |
YieldRate |
Yield, expressed as a percentage (dividends or interest yield), of the underlying asset price. This rate is interpreted as a continuously compounded rate unless specified otherwise in the YieldType argument. |
Optional. The frequency of the observations while collecting the AveragePrice. Note: only applied to the Geometric Average. If omitted, ContinuousSample is used as the default. |
|
MarketPrice |
Optional. The selling price of the option in the marketplace. This input is required when implied volatility and strike are calculated. Price must be > 0. |
TimeFormat |
Optional. Alphanumeric value indicating the format of the time arguments (i.e. TimeExpire). If omitted, Days are used as the default. Specified as either: •Days = 0 or "D" (case insensitive) •Years = 1 or "Y" (case insensitive) |
Optional. Alphanumeric value indicating the type of InterestRate to use when evaluating the option. This value is converted to Continuously Compounded for the calculations. If omitted, a Continuously Compounded rate is used. |
|
Optional. Alphanumeric value indicating the type of YieldRate to use when evaluating the option. This value is converted to Continuously Compounded for the calculations. If omitted, a Continuously Compounded rate is used. |
Example
Calculate all of functions for an average strike call option whose asset price 0.75 years from expiration is $25, the risk-free interest rate is 5.0% per annum, the yield rate is 3.0% per annum, and the annual volatility is 20%. All of the rates are considered continuous. So, |
Input |
|
Output |
||||
Variable |
Value |
|
Function |
Name |
Geometric |
Arithmetic |
OptionType |
Call |
|
1 |
Theoretical: |
1.096360 |
1.064409 |
Asset |
25 |
|
2 |
Delta: |
0.043854 |
0.042576 |
InterestRate |
5% |
|
3 |
Gamma: |
0.000000 |
0.000000 |
YieldRate |
3% |
|
4 |
Theta: |
-0.002131 |
-0.002015 |
TimeExpire |
0.75 |
|
5 |
Implied Vol.: |
0.181187 |
0.186707 |
Volatility |
20% |
|
6 |
Vega: |
0.051359 |
0.066625 |
TimeFormat |
Years |
|
7 |
Rho: |
0.044804 |
0.043088 |
MarketPrice |
1 |
|
8 |
Psi: |
-0.051558 |
-0.049659 |
|
|
|
9 |
Lambda: |
1.000000 |
1.000000 |
For a further example on this model see the included Excel Template located in the root directory of the add-in. This example can be accessed through the Asian Template menu item after the add-in has been installed properly.
A list of all of the possible Error Messages is included for convenience.