Short Selling: A known unknown. ECMI Commentary No. 23, 29 May 2009

Fears of systemic meltdown following the collapse of Lehman Brothers in September 2008 led to uncoordinated regulatory interventions around the world to ban or restrict short selling, a technique that allows one to profit from falling stock prices. The suspicion that ‘bear raids’ were having a negative impact on stock prices in general and financial stocks in particular motivated these regulatory developments. The ban on short selling reignited a long-standing debate on this controversial technique. This ECMI Commentary explores three fundamental questions posed by short selling. The first issue is of a conceptual nature: Is short selling legitimate and, if so, is it beneficial for financial markets? The second issue is: What is the difference between naked and covered short selling? The third question is legal in nature: Is short selling consistently defined across jurisdictions