Hey guys,

I want to calculate market cap as a measure of size (on a daily basis if possible). I have the following data

- fiscal year-end data from Compustat (shares outstanding x fiscal year-end closing price) = this gives me marketcap only on an annual basis

- daily CRSP stock prices and shares outstanding (daily price x daily shares outstanding) = marketcap on a daily basis

However, I was wondering about two things:

1) The shares outstanding between Compustat and CRSP differ significantly. Why is that?

2) If I calculate the marketcap with CRSP data only, do I need to adjust the prices and the shares before calculation (with the two adjustment factors, one for price and one for shares)?

Thanks