The effect of short-sale restrictions: another perspective

Purpose The purpose of this paper is to examine the effect of short-sale restrictions (SSR) with particular emphasis on their impact on the liquidity and informed trading in the stock and option markets. Design/methodology/approach Using a panel regression with controls for volatility, VIX and matched stocks, this study examines the effect of the short-sale ban (SSB) on stock and option liquidity, expressed in terms of spread and volume. In addition, the PIN and option information share (OIS) measures have been used to analyze its impact on informed trading in those related markets. Findings The results suggest that the SSB leads to a significant reduction in the liquidity of the affected stocks and their options. However, no significant change in the trader composition can be detected. This result is consistent to the short-prohibition effect predicted by Diamond and Verrecchia (1987). Research limitations/implications Due to the sizeable data required to estimate the PIN and OIS measures, only a select sample of optionable stocks has been examined. Originality/value This study offers both academics and policy makers some useful insights into the effect of SSR on trading activities in both stock and option markets. From a policy perspective, it clearly demonstrates that regulatory changes targeting a specific market also affect other related markets via the arbitrage link between them.