Stochastic Calc is part of the whole host of things that are irrelevant to trading, i doubt banks/"pro" traders use it, they want you to think they use it so they seem smart and clever and so people fight for their services and superior brain power, academics reinforce this so their lives have meaning.

Skill Lev said it right financial maths is nothing to do with trading, VAR, Black Scholes, random walk theory is all sh**...it has no relevance in real life, how can the markets be random on one hand and then have 3/4 sigma moves multiple times in a week, the probability of a 3 sigma moves once in ages is something like 0.01% (or around this region in gaussian distribution, which is what black scholes, Var all assume)...

in conclusion, black scholes is the perfect example of the application of fin maths to trading, traders say they use it, academics think they are clever, but when it comes down to it they trade the way they always did, through feel.