MIT LFE Working Paper by Pan, J. and A. Poteshman, 2003
...Performing daily crosssectional analyses from 1990 to 2001, we find that buying stocks with low put/call ratios and selling stocks with high put/call ratios generates an expected return of 40 basis points per day and 1 percent per week. ...In contrast to the equity options market, we do not find any evidence of informed trading in the index options market.
