This study has examined the ten most shorted shares belonging to the Swedish Stockholm Stock Exchange's Large Cap list, by following randomly selected financial institutions that have chosen to take short positions. The purpose of the study is to investigate whether it is possible for short sellers to generate an excess return compared to the index OMXS30GI. The theory is mostly about short selling in general, efficient market hypothesis, behavioral finance, opponents of short selling, technical analysis of an index and the theory also includes previous research regarding short selling. The method used is based on collected secondary data from different databases. Via the secondary data, we have artificially followed randomly selected financial institutions that have glossed over and done the same as them to see if it can generate an excess return. In this study we will not take the cost associated with short selling into account which normally would be costs as margin interest, stock borrowing costs and commissions to brokers. The results show that it is possible for short sellers to generate an excess return that outperforms index OMXS30GI. We can also conclude that short sellers follow a pattern that indicates that they do not act in a way to destroy market efficiency and we can question whether the market is efficient or not.

Introduktion: Blankning är ett sätt för en investerare att tjäna på att bolagets aktiekurs faller och har anklagats för att vara bakomliggande orsak till flera finansiella kriser. Det finns olika anledningar till att ett bolag blankas, likaså kan ett bolag påverkas av blankningen på olika sätt. Den befintliga forskningen behandlar främst den amerikanska marknaden och de tekniska åtgärder bolagen utövar för att minska blankning. Därmed finns det en lucka i forskningen kring huruvida svenska bolag verkställer strategier eller inte för att mildra blankning.   Syfte: Syftet med studien är att undersöka om svenska bolag verkställer strategier för att motverka blankningsnärvaro och förstå varför bolag har valt att styra på ett visst sätt vid en blankningssituation. Metod: Studien genomfördes med en kvalitativ forskningsansats och nyttjar empirisk såväl som teoretiskt material för att kontrastera den teoretiska referensramen med upptäckter i den empiriska data. Den primära datainsamlingen utgörs av semistrukturerade intervjuer med fyra av de femton mest blankade bolag enligt Finansinspektionen för april 2021 där analysering av den empiriska data har följt en trestegsprocess bestående av beskrivning, systematisering och kombination.   Slutsats: Studien har visats sig att de fyra bolag som har intervjuats inte sysslar med aktiva strategier mot blankning eftersom det finns en överensstämmande bild bland bolagen att det ska vara en fri marknad och att aktörerna får ta egna beslut. Resultatet visar att de svenska bolagen fokuserar på det långsiktiga tillväxt och att bibehålla transparens gentemot marknaden som i slutändan ska rättfärdiga deras värdering. / Introduction: Short selling is a way for an investor to gain profit when a stock drops in price and the practice has been accused of being the reason behind several financial crises. There are various reasons why a company gets shorted, which affects the company in many ways. Previous studies have only processed short selling in the US market and technical actions that companies enforce to reduce short interest. However, there is a lack of studies about the Swedish market and strategies, if any, that Swedish companies work with to reduce short interest. Purpose:  The purpose of this study is to examine whether Swedish firms execute strategies or not to counteract the presence of short selling positions and understand why the firms have chosen to manage in a certain way during a short selling situation.  Method: The study was conducted with a qualitative approach and uses both empirical and theoretical material to contrast the theoretical framework with the discoveries from empirical data. The primary data collection consists of semi-structured interviews with four out of the fifteen most shorted companies according to Finansinspektionen for April 2021, whereas the data was analyzed using the three-step process consisting of description, systematisation, and combination. Findings: The study shows that the four firms interviewed do not actively work with strategies against short selling as there is a consensus amongst the firms that the market should operate freely and that the participants make their own decisions. The result shows that the Swedish firms focus on the long-term growth of the company and to maintain transparency towards the market which in the end should justify their valuation.

This dissertation consists of three essays. The first essay focuses on idiosyncratic volatility as a primary arbitrage cost for short sellers. Previous studies document (i) negative abnormal returns for high relative short interest (RSI) stocks, and (ii) positive abnormal returns for low RSI stocks. We examine whether these market inefficiencies can be explained by arbitrage limitations, especially firms' idiosyncratic risk. Consistent with limits to arbitrage hypothesis, we document an abnormal return of -1.74% per month for high RSI stocks (>=95th percentile) with high idiosyncratic volatility. However, for similar level of high RSI, abnormal returns are economically and statistically insignificant for stocks with low idiosyncratic volatility. For stocks with low RSI, the returns are positively related to idiosyncratic volatility. These results imply that idiosyncratic risk is a potential reason for the inability of arbitrageurs to extract returns from high and low RSI portfolios. The second essay investigates market efficiency in the absence of limits to arbitrage on short selling. Theoretical predictions and empirical results are ambiguous about the effect of short sale constraints on security prices. Since these constraints cannot be eliminated in equity markets, we use trades from futures markets where there is no distinction between short and long positions. With no external constraints on short positions, we document a weekend effect in futures markets which is a result of asymmetric risk between long and short positions around weekends. The premium is higher in periods of high volatility when short sellers are unwilling to accept higher levels of risk. On the other hand, riskiness of long positions does not seem to have a similar impact on prices. The third essay studies investor behaviors that generate mispricing by examining relationship between stock price and future returns. Based on traditional finance theory, valuation should not depend on nominal stock prices. However, recent literature documents that preference of retail investors for low price stocks results in their overvaluation. Motivated by this preference, we re-examine the relationship between stock price and expected return for the entire U.S. stock market. We find that stock price and expected returns are positively related if price is not confounded with size. Results in this paper show that, controlled for size, high price stocks significantly outperform low price stocks by an abnormal 0.40% per month. This return premium is attributed to individual investors' preference for low price stocks. Consistent with costly arbitrage, the return differential between high and low price stocks is highest for the stocks which are difficulty to arbitrage. The results are robust to price cut-off of $5, and in different sub-periods. / Ph. D.

本文著重在探討現股放空限制與交易成本對期貨錯價之影響。以門檻自我迴歸與續航門檻自我迴歸模型分析期貨錯價之非線性過程，我們發現錯價有回歸平均(mean reversion)的現象。當期貨錯價為正時(套利策略為買現貨賣期貨)，交易量對錯價影響為負；但若期貨錯價為負(套利策略為賣現貨買期貨)，考慮到昂貴的放空成本(costly short sell hypothesis)，交易量對錯價的影響將是較不明確的。 / This article highlights the impact of short selling restrictions and trading costs on the relation on futures mispricing error. Within threshold autoregression model (TAR) and momentum threshold autoregressive model (M-TAR), the influence of optimal arbitrage trading on the mispricing is analyzed. Results concerning trading volume and level, mean reversion in mispricing error, and the model which describes mispricing process better. The empirical evidence suggests that trading costs and short selling costs are influential factors for the mispricing behavior. Moreover, the futures trading volume affects mispricing level significantly.

Zero Magic is a trick for the financial markets, which has the capacity to undermine the perceived value of a publicly traded company and profit from this. Short selling is a way of profiting from loss: Making money if and when a target company loses in value. It is a fundamental market activity that goes as far back as the first stock, yet to this day little is publicly known about the strategies employed by short sellers. On the US exchanges there is no requirement for hedge funds to disclose short positions, and in other jurisdictions such requirements are very limited. Zero Magic was developed by covertly infiltrating a secretive hedge fund specializing in short selling, and reverse engineering its methods. In brief, the hedge fund’s trading strategy is based on identifying suitable short selling targets through analyzing networks of corruption, and then framing critical newsworthy stories about these target companies that can be anonymously distributed among journalists. Profit is gained when a target company loses in value. Rigorous measures are taken by the fund never to be identified as the source of a negative campaign.Access to the hedge fund was gained through the art world. The founder and co-director routinely supports artists and art institutions and is said to have gotten the idea for his fund when looking at a Mark Lombardi drawing (an artist known for mapping networks of power and corruption). It is hard to tell whether the founder’s engagement with art merely entertains personal vanity, or if it functions more strategically as a means of “secret publicity” for the fund; giving access to investors, while staying under the radar of more mainstream public relations. Covert techniques such as hidden recordings and proxy researchers were used to uncover the fund’s methods. With the assistance of Théo Bourgeron, sociologist of finance, Zero Magic not only reconstructs the workings of the trading strategy, but offers a fully operational magic gimmick. The magic gimmick is a computer program providing non-expert users the means to identify relevant short selling targets (companies with weak “valuation conventions”), and a step-by-step guide to undermining their perceived value. With this gimmick one can execute a successful short sale without any previous contacts in the investor community or access to insider information. A US patent application for the trick was filed in January 2016.The artistic PhD “Zero Magic: Shifting the Valuation Convention” concludes with a stage performance and a magic box:The stage performance, “On a Long Enough Timeline the Survival Rate for Everyone Drops to Zero” with magician Malin Nilsson, performed on May 11 and 12, 2016, at Cirkus Cirkör, Stockholm. Through the ticket sales, audience members are drawn into the Zero Magic trick, buying into the predicted future loss of a target company. The magic box, prepared for public archives, contains the Zero Magic computer software, a US patent application for a “Computer Assisted Magic Trick Executed in the Financial Markets” and four historical examples of magic tricks played out beyond the stage, in the world at large.

Die fondsgebundene Umsetzung einer Long/Short-Strategie stößt schnell an ihre Grenzen, wenn die Regulierungserfordernisse der UCITS IV-Richtlinie 2009/65/EG als rechtlicher Rahmen für den Investmentfonds maßgeblich sind. Die betreffenden Regelungen verlangen einerseits eine diversifizierte Ausrichtung des Portfolios und beschränken das Universum an investierbaren Vermögenswerten auf finanzielle und liquide Produkte. Andererseits führen sie zu einer wesentlichen Begrenzung der zulässigen Anlagetechniken. Die Möglichkeiten zur Hebelinvestition sind streng limitiert und das Durchführen von Leerverkäufen wird vollständig ausgeschlossen. Der Anknüpfungspunkt, die Performance einer Short-Position dennoch in den Fonds zu integrieren, ist die Abkehr von der direkten und physischen Umsetzung hin zu einer indirekten und synthetischen Einbindung, wie sie durch den Einsatz von Derivaten möglich ist. Um die Auswirkungen der Derivate auf das Risiko- und Renditeprofil der Investmentfonds überschaubar und kontrollierbar zu halten, wird die Intensität des Derivatehandels durch das Festsetzen von Risikolimits auf ein vertretbares Maß beschränkt. Die Wahl eines konkreten Derivats beeinflusst die technische Umsetzung der synthetischen Positionsbildung und bestimmt deren assoziierte Vorgaben im Kontext des Risikomanagements. Insofern Derivate bei der Strategieausrichtung des UCITS-Fonds ausgeschlossen werden, lassen sich Short-Positionen lediglich gegenüber aggregierten Exposures in Form einer Dachfondskonstruktion berücksichtigen. Das Ausarbeiten kapitalrechtlicher Vorgaben und das darauf basierende Ableiten von praxisrelevanten Investitionsansätzen, zur Abbildung der Short-Positionen innerhalb einer fondsgebundenen Long/Short-Strategie, stehen im Fokus.

Short selling is important for price efficiency as it helps negative information to be incorporated into prices. As short selling requires borrowing stock in advance, the equity lending market plays a central role in price efficiency. For instance, when the costs of borrowing certain equities are high, these stocks are likely to be overpriced. Unfortunately, not much is known about the equity lending market, particularly the Brazilian market. Here, we have investigated a particular feature of the equity lending contract, namely, the lender recall option. Lending contracts either i) allow the lender to recall the stock at an earlier date than initially agreed, or ii) allow no early recall, that is, they are fixed term contracts. We have derived a simple model for recall option pricing and confirmed the model empirically / A venda descoberta desempenha uma importante participação na eficiência da precificação de ativos, pois permite incorporar informações negativas aos seus preços. Como a venda descoberta requer que um ativo seja alugado previamente, o mercado de aluguel de ativos tem um papel central na formação eficiente de preços. Por exemplo, quando os custos de aluguel são altos, ativos estão provavelmente sobrevalorizados. Infelizmente pouco se conhece a fundo sobre o mercado de aluguel de ativos. Neste artigo, investigamos uma característica do aluguel de ações, propriamente dita, a opção de liquidação antecipada pelo doador. Contratos de aluguel, quanto a este aspecto, podem i) permitir que o doador requeira suas ações antes do prazo acordado ou ii) não permitir esta opção, possuindo prazo fixo. Derivamos um modelo simples de precificação desta opção e confirmamos o modelo empiricamente

Syfte: Syftet med den här uppsatsen är att undersöka om blankade bolag har lägre grad av earnings quality än icke-blankade bolag. Metod: Kvantitativ metod, t-test för två populationer som antar olika varianser. Resultat och slutsats: Resultatet i den här studien visar att blankade bolag inte har lägre grad av earnings quality än icke-blankade bolag. Resultatet visar även att icke-blankade bolag har lägre grad av earnings quality än blankade bolag. Därför kan jag inte uttala mig om huruvida blankare använder earnings quality vid tagandet av blankningspositioner / Purpose: The purpose of this essay is to examine if shorted companies have poorer earnings quality than non-shorted companies Method: Quantitative analysis, t-test for two-sample assuming unequal variances Result and conclusion: The results of this study show that shorted companies do not have poorer earnings quality than non-shorted companies. The results also indicate that non-shorted companies have poorer earnings quality than shorted companies. Thus, I cannot comment on whether short sellers are using information about earnings quality when taking short positions

本研究主要探討兩項關於融券交易的議題。首先，本研究發現巨量融券與續後的股價反應呈現顯著的負相關。再者，進一步探究盈餘宣告前的融券信用交易是否與非盈餘宣告的時間存有差異。本研究是採用在台灣證券交易所上市之股票並觀察其盈餘宣告前五日之融券交易行為。實證結果發現盈餘宣告前的融券與盈餘宣告後的股價反應存在負向關係，顯示可能有私有資訊的交易者在盈餘宣告前進行融券交易。接下來本研究進一步使用基本財務比率中的帳面價值對市價比將樣本區分成價值型與成長型之股票，發現擁有較低比率之公司較受融券交易者之青睞。本研究希望研究成果能對證券市場主管機關在制訂法律與提供更即時、更廣泛的信用交易資訊揭露給投資大眾參考。 / This research examines two issues of short-selling transactions.First,we find a strong negative relationship between short interest and subsequent abnormal returns.The second is whether short-selling in the days leading up to an announcement differs from short-selling in times when no announcement is imminent.We examine short-selling behavior of investors in the five days prior to the earnings announcements of Taiwan Stock Exchange (TSE)listed firms.The tests provide evidence that there might exist informed trading in pre-announcement short-selling because they reveal that abnormal short-selling is significantly linked to post-announcement stock returns.A high level of unusual pre-announcement short-selling is an indicator of future stock returns at earnings announcement.Also,the tests indicate that short-sellers typically are more active in stocks with low book-to-market ratio valuation.We believe that these results should encourage financial market regulators to consider providing more extensive and timely disclosures of short-selling to investors.

Prior studies have shown that returns exhibit certain predictable patterns that are inconsistent with the mainstream finance theory. In this thesis, I explore the behaviour of returns following three different types of market events with a particular focus on behavioural and non-behavioural factors that are attributable to the predictability of post-event returns. This thesis consists of three self-contained empirical essays. The first essay examines the information role of large S&P500 futures trades (commercial, noncommercial, dealers, asset managers, and hedge funds) in shaping future index returns. I find that commercial firms’ net trading level appears positively correlated with future index returns but the relationship is not stable across time. Based on more recent data, hedge funds appear superior in terms of access to information and/or trading ability but this advantage is only preserved at high frequency. Therefore, the current weekly Commitment of Traders (COT) report - published with a three-day delay - prevents timely public access to this type of information. Also, trading signals based on two of the more popular position-based sentiment indicators do not produce significant average returns. Overall, this calls into question the reliability of COT-based trading signals used by market professionals. The second essay studies the impacts of short sellers’ trading in shaping the behaviour of stock returns following extreme price moves using data from stock market in mainland China where short sales were initially prohibited. Extreme price moves occurring under non-prohibitive/prohibitive short-sale constraints are defined as shortable/non-shortable events. I find shortable events exhibit less post-event price drift/reversals than non-shortable ones, indicating an increase in the efficiency of stock prices reacting to unexpected events. Further analysis of short sellers’ trading activities on the price event days suggests that they are successful in trading informed price shocks but not in trading uninformed ones. Finally, I find evidence of massive short-covering that amplifies price shocks. The third essay investigates investors’ reaction to stock market rumours using data from China where listed companies are required to clarify rumours appearing in the media. I find that post-clarification abnormal returns exhibit continuation of pre-clarification momentum for rumours that are not denied by the listed companies and reversals for those which are denied. These results suggest that investors are unable to distinguish the reliable rumours from the false ones, as they under-react to rumours containing material information and over-react to those without. Further regression analyses on post-clarification abnormal returns using various subsamples of rumour events show that investors respond more efficiently to rumours when they are more informed about news topics or the rumoured companies.