Short-Sale Constraints and Options Trading: Evidence from Reg SHO

Yi-Wen Chen, Sheng-Syan Chen, and Robin K. Chou

We examine the effects of a temporary suspension of short-sale price tests on the options market. Consistent with the notion that put option trading substitutes for short selling, we find a significant reduction in put option volume. In addition, pressure on put option prices significantly declines, violations of the put-call parity become significantly less frequent, and option volume becomes less informed. Our findings add clarity to a long-standing debate on whether investors use options to circumvent equity short selling restrictions.