Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 110-115).

Naked short selling occurs when a short seller fails to deliver shares on the settlement day. The business press and many corporate managers characterize it as abusive price manipulation, alleging that selling nonexistent shares causes a price decline regardless of fundamentals. To curtail the practice, the SEC issued regulations, first to restrain and later to prohibit all naked short selling (i.e., Reg. SHO in 2004 and its amendment in 2009). Contrary to allegations, I find that the naked short selling component of total short interest is significantly associated with accounting and market fundamentals, indicating proper information usage. Further, naked short interest is highly significant in predicting one-quarter ahead abnormal stock returns, and it dominates covered short interest when both measures are included. I also calculate returns from a zero-investment trading strategy that buys (sells) shares with low (high) levels of both covered and naked short interest. I find abnormal returns are approximately 3.9 times larger than when using only covered short interest. Empirical evidence therefore indicates that recent actions by regulators to eliminate naked short selling are likely to impede arbitrage and thereby reduce market efficiency.

published_or_final_version / abstract / Business / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Problembakgrund/Problemdiskussion: Mitt under brinnande finanskris 2008 tvingades den välkända storbanken Lehman Brothers ansöka om konkurs. Bankens konkurs i kombination andra finansiella instituts var startskottet på en intensiv debatt beträffande flertalet företeelser på den finansiella marknaden. En av dessa företeelser var blankning. Kritiker menar att blankning bidrog till att destabilisera en redan skakad marknad och generera omotiverat stora prisras på aktiemarknaden. Förespråkarna menar och andra sidan att det inte är blankning som formar marknaden utan att det endast är en strategi baserad på brister i marknaden. Oavsett vilken sida som står närmast sanningen ledde debatten till att EU instiftade ett nytt regelverk, som till viss del begränsar blankning och ökar dess transparens. Den första november 2012 började detta regelverk tillämpas i Sverige, och innebär kortfattat att alla större blankningsorders ska offentliggöras av Finansinspektionen (FI). Den stora frågan är därmed vilket bidrag blankning har på den svenska aktiemarknaden efter att detta regelverk börjat tillämpas. I ett försök att undersöka detta kommer den publicerade informationen av FI att bearbetas i denna studie. Problemformulering/Syfte: Utifrån följande frågeställning kommer studien att fokusera på huruvida blankning påverkar volatiliteten på den svenska aktiemarknaden: Påverkar blankning aktieprisvolatiliteten?Syftet är därmed att klargöra om FIs offentliggörande av blankningsorders har någon effekt på volatiliteten på den svenska aktiemarknaden. Teoretisk referensram: Studiens resultat har analyserats och diskuterats utifrån följande teorier: den Effektiva marknadshypotesen, den Adaptiva marknadshypotesen, Informationsasymmetri & Signalteori, Prismanipulation och Beteendebaserad finansiell ekonomi. I detta avsnitt har även tidigare studier inom ämnesområdet behandlats. Metod: För att undersöka om det föreligger ett samband mellan blankning och volatilitet på den svenska aktiemarknaden har en kvantitativ studie genomförts. Studien är baserad på blankningsorders för 53 bolag, som FI:s offentligt publicerat mellan den första november 2012 till den sista januari 2014. Genom användandet av multipla regressioner och ett antal förklaringsvariabler har det statistiskt undersökts om det förelegat något samband mellan bolagens dagliga varians och tillfällen när blankning förekommit. Empiri/Analys/Slutsats: Utifrån de statistiska tester som genomförts i det empiriska kapitlet går det inte att dra några slutsatser beträffande om publicerade blankningsorders har någon effekt på volatiliteten. Därmed finns det inget statistiskt stöd för att blankning påverkar volatiliteten på den svenska aktiemarknaden.

This dissertation investigates whether short sellers establish short positions prior to accounting restatement announcements and whether the levels of short interest are related to the severity of restatements. Using 565 firms with restatement disclosure during the period of 1995 to 2002 and matched control firms with no restatements announcements, I find that the level of short interest is higher for the sample firms compared to the control firms in the months surrounding the announcements. The level of short interest increases as the restatement announcement date approaches and declines thereafter. Related to severity of restatement, I find that the level of short interest in the pre-disclosure period is higher for restatements involving fraud and the revenue accounts. There exists limited evidence that the pre-disclosure level of short interest is positively associated with the number of quarters restated and the magnitude of the restatements. Finally, I find cumulative abnormal returns surrounding the announcements are more negative for restatement firms that have a higher level of short interest. These results suggest that short sellers are highly sophisticated investors who can see through accounting manipulation and consequently profit from their knowledge.

This dissertation investigates whether short sellers establish short positions prior to accounting restatement announcements and whether the levels of short interest are related to the severity of restatements. Using 565 firms with restatement disclosure during the period of 1995 to 2002 and matched control firms with no restatements announcements, I find that the level of short interest is higher for the sample firms compared to the control firms in the months surrounding the announcements. The level of short interest increases as the restatement announcement date approaches and declines thereafter. Related to severity of restatement, I find that the level of short interest in the pre-disclosure period is higher for restatements involving fraud and the revenue accounts. There exists limited evidence that the pre-disclosure level of short interest is positively associated with the number of quarters restated and the magnitude of the restatements. Finally, I find cumulative abnormal returns surrounding the announcements are more negative for restatement firms that have a higher level of short interest. These results suggest that short sellers are highly sophisticated investors who can see through accounting manipulation and consequently profit from their knowledge.

This dissertation consists of two empirical essays on the interactions among three financial markets, namely, the stock market, the options market, and the equity lending market. In the first essay, we study the role of analysts and options traders in the information transmission between options and stock markets. We first show that the predictive power of option-implied volatilities (IVs) on stock returns is more than doubled around analyst-related events, indicating a significant proportion of the options predictability on stock returns comes from informed options traders’ information about upcoming analyst-related news. We examine three explanations for this finding: tipping, reverse tipping and common information. We find that analyst tipping to options traders is the most consistent explanation of these predictive patterns. In the second essay, we examine the relationship between put options and short sales. We are able to separate the speculative demand of informed traders from the hedging demand of options market makers in the lending market. We find that the put option bid-ask spread and put option trading volume both increase with the equity lending fee. However, we also find that put option trading volume decreases with the lending fee for banned stocks during the 2008 Short-Sale Ban period, i.e., when only options market makers can short. These findings suggest that when informed traders are allowed to short, their speculative demand dominates and drives the substitution that is observed between the two financial instruments. Nevertheless, the “complementarity” of these financial instruments might prevail when options market makers significantly reduce the supply of put options because of high hedging costs. / published_or_final_version / Economics and Finance / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 57-61).