We examine how the confusion and regulatory uncertainty generated by the imposition of short sale restrictions in September 2008 impacted equity option markets. We uncover three primary findings. First, investors seeking short exposure in financial stocks did not migrate to the option market to...

Agency mortgage-backed securities trade simultaneously in a market for specified pools (SPs) and in the to-be-announced (TBA) forward market. TBA trading creates liquidity by allowing thousands of different MBS to be traded in a handful of TBA contracts. SPs that are eligible to be traded as...