optstockbyeqp

Price stock option from Equal Probabilities binomial tree

Syntax

[Price,PriceTree] = optstockbyeqp(EQPTree,OptSpec,Strike,Settle,ExerciseDates)

[Price,PriceTree] = optstockbyeqp(___,AmericanOpt)

Description

[Price,PriceTree] = optstockbyeqp(EQPTree,OptSpec,Strike,Settle,ExerciseDates) returns the price of a European, Bermuda, or American stock option from an Equal Probabilities binomial tree.

[Price,PriceTree] = optstockbyeqp(___,AmericanOpt) adds an optional argument for AmericanOpt.

Examples

Price an American Stock Option Using an EQP Equity Tree

This example shows how to price an American stock option using an EQP equity tree by loading the file deriv.mat, which provides EQPTree. The EQPTree structure contains the stock specification and time information needed to price the American option.

load deriv.mat

OptSpec = 'Call';
Strike = 105;
Settle = '01-Jan-2003';
ExerciseDates = '01-Jan-2006';
AmericanOpt = 1;

Price = optstockbyeqp(EQPTree, OptSpec, Strike, Settle, ... 
ExerciseDates, AmericanOpt)

Price = 12.2632

Price a Bermudan Stock Option Using a EQP Equity Tree

Load the file deriv.mat, which provides EQPTree. The EQPTree structure contains the stock specification and time information needed to price the Bermudan option.

load deriv.mat;

% Option
OptSpec = 'Call';
Strike = 105;
Settle = '01-Jan-2003';
ExerciseDatesBerm={'15-Jan-2004','15-Jul-2004','15-Jan-2005','15-Jul-2005'};

Price the Bermudan option.

Price= optstockbyeqp(EQPTree, OptSpec, Strike, Settle, ExerciseDatesBerm)

Warning: Some ExerciseDates are not aligned with tree nodes. Result will be approximated.

Price = 12.0255

Input Arguments

EQPTree — Stock tree structure

structure

Stock tree structure, specified by using eqptree.

Data Types: struct

OptSpec — Definition of option

character vector with value 'call' or 'put' | cell array of character vectors with values 'call' or 'put'

Definition of option, specified as 'call' or 'put' using a NINST-by-1 cell array of character vectors.

Data Types: char | cell

Strike — Option strike price values

nonnegative integer

Option strike price value, specified with a NINST-by-1 or NINST-by-NSTRIKES depending on the option type:

• For a European option, use a NINST-by-1 vector of strike prices.

• For a Bermuda option, use aNINST-by-NSTRIKES matrix of strike prices. Each row is the schedule for one option. If an option has fewer than NSTRIKES exercise opportunities, the end of the row is padded with NaNs.

• For an American option, use a NINST-by-1 of strike prices.

Note

The interpretation of the Strike and ExerciseDates arguments depends upon the setting of the AmericanOpt argument. If AmericanOpt = 0, NaN, or is unspecified, the option is a European or Bermuda option. If AmericanOpt = 1, the option is an American option.

Data Types: double

Settle — Settlement date or trade date

serial date number | date character vector

Settlement date or trade date, specified as a NINST-by-1 vector of date character vectors or serial date numbers.

Note

The Settle date for every option is set to the ValuationDate of the stock tree. The option argument Settle is ignored.

Data Types: char | double

ExerciseDates — Option exercise dates

serial date number | date character vector

Option exercise dates, specified as a NINST-by-1,NINST-by-2, or NINST-by-NSTRIKES using serial date numbers or date character vectors, depending on the option type:

• For a European option, use a NINST-by-1 vector of dates. Each row is the schedule for one option. For a European option, there is only one ExerciseDates on the option expiry date.

• For a Bermuda option, use a NINST-by-NSTRIKES vector of dates. Each row is the schedule for one option.

• For an American option, use a NINST-by-2 vector of exercise date boundaries. The option can be exercised on any date between or including the pair of dates on that row. If only one non-NaN date is listed, or if ExerciseDates is a NINST-by-1 vector, the option can be exercised between ValuationDate of the stock tree and the single listed ExerciseDates.

Note

The interpretation of the Strike and ExerciseDates arguments depends upon the setting of the AmericanOpt argument. If AmericanOpt = 0, NaN, or is unspecified, the option is a European or Bermuda option. If AmericanOpt = 1, the option is an American option.

Data Types: double | char

AmericanOpt — Option type

0 European or Bermuda (default) | integer with values of 0 or 1

(Optional) Option type, specified as NINST-by-1 vector of integer flags with values:

• 0 — European or Bermuda

• 1 — American

Data Types: single | double

Output Arguments

Price — Expected price of option at time 0

vector

Expected price of the vanilla option at time 0, returned as a NINST-by-1 vector.

PriceTree — Structure containing trees of vectors of instrument prices for each node

structure

Structure containing trees of vectors of instrument prices and a vector of observation times for each node. Values are:

• PriceTree.PTree contains the clean prices.

• PriceTree.tObs contains the observation times.

• PriceTree.dObs contains the observation dates.