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arrun
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Joined: August 1st, 2006, 6:14 am

Stock Price model

August 11th, 2006, 2:20 pm

Dear all,Can any one please explain me why any stock price is modeled like this?dS/S = m*dt + sigma*dw[t], where w[t] is weiner/brownian processThanks and regards,Arun
 
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chromo
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Joined: June 16th, 2006, 8:55 am

Stock Price model

August 11th, 2006, 2:29 pm

because the model is1) a member of the class of affine process which have very useful properties. Including nice clean analytical solutions to some pricing problems.2) qualitatively similar to behaviour of actual price series3) better than any of the alternatives - the alternatives either don't resemble the actual price processes or don't give such pretty solutionsif this is too simple for you, try jump diffusions.
 
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rimaephosie
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Joined: May 21st, 2006, 7:40 pm

Stock Price model

August 12th, 2006, 9:02 pm

One thing, because the prices are not stationary, the returns are.