LAUSR

We show that the 2008 short-sale ban significantly enhanced the return predictability of put-call parity violations and attribute the significant increase in violations to stock over-valuation. The top quantile put-call parity violation portfolio under-performs the lowest quantile portfolio by a risk-adjusted daily return of 2.8% during the ban period. Panel regression analysis documents that a significant increase in return predictability during the ban is more pronounced for stocks with liquid options, further corroborating our results. Our findings are robust to a number of controls aimed at alleviating concerns that other concurrent policy changes and events might be driving our results.