it depends on how applied the class is. A deep understanding of stochastic calculus is not required for "P-Quants", the type of person that lives in the physical word of forecasting and risk. That being said understanding the type of models that get used by the Q-Side (requiring lots of stochasic theory) is a useful skill to have.
Like John said, if you wanted to forecast option returns, you need to have a good understanding of the statistical properties of options timeseries/cross sections to build either a risk model or a forecast model. Understanding the depths of stochastic calculus is not required here, but understanding black scholes (and the underlying assumptions) could be useful.
In this regard a stochastic calculus class will help you.
For a better distinction between p-quants and q-quants take a look at some of the work attilio maucci has done.
article here:
http://symmys.com/node/62
p-quant class here:
http://symmys.com/arpm-bootcamp/program