The following post comes to us from Ekkehart Boehmer
, Professor of Finance at EDHEC Business School; Charles Jones
, Professor of Finance and Economics at Columbia University; and Xiaoyan Zhang
of the Krannert School of Management at Purdue University.
In September 2008, the U.S. Securities and Exchange Commission (SEC) temporarily banned most short sales in nearly 1,000 financial stocks. In our paper, Shackling Short Sellers: The 2008 Shorting Ban, forthcoming in the Review of Financial Studies, we examine the ban’s effect on market quality, shorting activity, the aggressiveness of short sellers, and stock prices. For the most part, financial economists consider short sellers to be the “good guys,” unearthing overvalued companies and contributing to efficient stock prices. Even as late as the summer of 2007, regulators in the United States seemed to share this view, as they made life easier for short sellers by repealing the New York Stock Exchange’s (NYSE’s) uptick rule and other short-sale price tests that had impeded shorting activity since the Great Depression (see Boehmer, Jones, and Zhang (2009) for an analysis of this event). However, short sellers are often the scapegoats when share prices fall sharply, and regulators in the United States did a sharp U-turn in 2008, imposing tight new restrictions on short sellers as the financial crisis worsened. In September 2008, the U.S. Securities and Exchange Commission (SEC) surprised the investment community by adopting an emergency order that temporarily banned most short sales in nearly 1,000 financial stocks. In this paper, we study changes in various liquidity measures, the rate of short sales, the aggressiveness of short sellers, and in stock prices before, during, and after the shorting ban. We compare banned stocks to a control group of nonbanned stocks to identify these effects.
…continue reading: Shackling Short Sellers: The 2008 Shorting Ban