Early Exercise of Call Options to Accelerate Application of Lower U.S. Tax Rates on Capital Gains

The current and widespread view in option trading is that early exercise of call options is suboptimal unless there are large dividend payments on the underlying stock (e.g., Finucane, 1997; Hull, J. C. (2008). Options, futures and other derivatives (7th ed.). Upper Saddle River, NJ: Prentice Hall; Poteshman & Serbin (2003)). Our study substantially refines this view by demonstrating that U.S. tax rules governing capital gain holding periods can create incentives for early exercise under certain conditions. Hence, this study adds to the factors that investors likely consider when making option exercise decisions. We further note that recent research documents early exercises in the absence of large dividends, and refers to these option exercises as “clearly irrational.” Predictions of early exercise from our tax-based model are consistent with the observed patterns of early exercise, suggesting that the criteria for denoting an option exercise as “irrational” should be refined to incorporate capital gain holding periods.