# supersharebybls

Determine price of supershare digital options using Black-Scholes model

## Syntax

``Price = supersharebybls(RateSpec,StockSpec,Settle,Maturity,StrikeLow,StrikeHigh)``

## Description

example

````Price = supersharebybls(RateSpec,StockSpec,Settle,Maturity,StrikeLow,StrikeHigh)` computes supershare digital options using the Black-Scholes option pricing model.```

## Examples

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This example shows how to compute the price of supershare digital options using Black-Scholes model. Consider a supershare based on a portfolio of nondividend paying stocks with a lower strike of 350 and an upper strike of 450. The value of the portfolio on November 1, 2008 is 400. The risk-free rate is 4.5% and the volatility is 18%. Using this data, calculate the price of the supershare option on February 1, 2009.

```Settle = datetime(2008,11,1); Maturity = datetime(2009,2,1); Rates = 0.045; Basis = 1; Compounding = -1; % create the RateSpec RateSpec = intenvset('ValuationDate', Settle, 'StartDates', Settle,... 'EndDates', Maturity, 'Rates', Rates, 'Compounding', Compounding, 'Basis', Basis); % define the StockSpec AssetPrice = 400; Sigma = .18; StockSpec = stockspec(Sigma, AssetPrice); % define the high and low strike points StrikeLow = 350; StrikeHigh = 450; % calculate the price Pssh = supersharebybls(RateSpec, StockSpec, Settle, Maturity,... StrikeLow, StrikeHigh)```
```Pssh = 0.9411 ```

## Input Arguments

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Interest-rate term structure (annualized and continuously compounded), specified by the `RateSpec` obtained from `intenvset`. For information on the interest-rate specification, see `intenvset`.

Data Types: `struct`

Stock specification for the underlying asset. For information on the stock specification, see `stockspec`.

`stockspec` handles several types of underlying assets. For example, for physical commodities the price is `StockSpec.Asset`, the volatility is `StockSpec.Sigma`, and the convenience yield is `StockSpec.DividendAmounts`.

Data Types: `struct`

Settlement or trade date for the basket option, specified as an `NINST`-by-`1` vector using a datetime array, string array, or date character vectors.

To support existing code, `supersharebybls` also accepts serial date numbers as inputs, but they are not recommended.

Maturity date for the basket option, specified as an `NINST`-by-`1` vector using a datetime array, string array, or date character vectors.

To support existing code, `supersharebybls` also accepts serial date numbers as inputs, but they are not recommended.

Low strike price values, specified as an `NINST`-by-`1` vector.

Data Types: `double`

High strike price values, specified as an `NINST`-by-`1` vector.

Data Types: `double`

## Output Arguments

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Expected prices for supershare option, returned as a `NINST`-by-`1` vector.

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### Supershare Option

A supershare option pays out a proportion of the assets underlying a portfolio if the asset lies between a lower and an upper bound at the expiry of the option.