Surprisingly, little is known about the effects of short-sale constraints on herd behaviour. Since institutional investors have come to dominate mature stock markets and rely extensively on short sales, constraining these traders may influence the asset pricing process. The literature on short-selling restrictions focusses mainly on a ban's impact on market efficiency, liquidity and overpricing. The authors examine bans on selected financial stocks in six countries during the 2008-2009 global financial crisis, which provided a setting to analyze the impact of short-sale restrictions. In particular, the authors focussed on short-sale constraints’ effect on institutional investors’ trading behaviour and the possibility of generating herding behaviour. They conclude that the empirical evidence shows that short-selling restrictions exhibit either no influence on herding formation or induce adverse herding.