This study documents that the abnormal stock returns are negative before unscheduled executive option awards and positive afterward. The return pattern has intensified over time, suggesting that executives have gradually become more effective at timing awards to their advantage, and possibly...

We estimate that 13.6% of all option grants to top executives during the period 1996-2005 were backdated or otherwise manipulated. Our study primarily focuses on grants that were unscheduled and at-the-money, of which we estimate that 18.9% were manipulated. The fraction is 23.0% before the new...