Reversal and momentum patterns in weekly stock returns: European evidence

We analyze short‐term reversal and medium‐term momentum patterns in weekly stock returns in Europe. Focusing on raw and stock‐specific returns, our empirical results show for both return specifications (a) a negative relation between weekly past returns and future returns in the short run and (b) a positive relation in the medium run. However, returns from reversal and momentum strategies based on stock‐specific returns are less volatile. In further analyses, we find short‐term reversal and medium‐term momentum patterns to be connected to stock characteristics. Looking at the potential causes of these effects, our results do not support the idea that short‐term reversal in weekly stock returns is due to an over‐ or underreaction to firm‐specific news nor that it is mainly driven by illiquidity. Medium‐term momentum in weekly stock returns, on the other hand, can be connected to behavioral biases. Our concluding tests confirm that our findings are robust among industries, in subperiods, for the January effect and in varying market states. Finally, while medium‐term momentum strategies remain profitable after accounting for transaction costs, short‐term reversal strategies can be mainly explained by transaction costs due to their high turnover.     

Time series momentum

We document significant “time series momentum” in equity index, currency, commodity, and bond futures for each of the 58 liquid instruments we consider. We find persistence in returns for one to 12 months that partially reverses over longer horizons, consistent with sentiment theories of initial under-reaction and delayed over-reaction. A diversified portfolio of time series momentum strategies across all asset classes delivers substantial abnormal returns with little exposure to standard asset pricing factors and performs best during extreme markets. Examining the trading activities of speculators and hedgers, we find that speculators profit from time series momentum at the expense of hedgers.     

Tactical allocation in commodity futures markets: Combining momentum and term structure signals

This paper examines the combined role of momentum and term structure signals for the design of profitable trading strategies in commodity futures markets. With significant annualized alphas of 10.14% and 12.66%, respectively, the momentum and term structure strategies appear profitable when implemented individually. With an abnormal return of 21.02%, our double-sort strategy that exploits both momentum and term structure signals clearly outperforms the single-sort strategies. This double-sort strategy can additionally be utilized as a portfolio diversification tool. The abnormal performance of the combined portfolios cannot be explained by a lack of liquidity, data mining or transaction costs.     

The Information Content of Insider Call Options Trading

We examine the information content of two forms of insider trading, insider buy-, and sell-call transactions. We find that the information carried by stand-alone call purchases has only a short-term impact on stock prices, but over a longer term, call purchases accompanied by stock purchases have a positive impact. Call purchases accompanied by stock sales signal negative information about the firm, suggesting that some insiders use complicated trading strategies to manipulate the market. Insider sell-call transactions are followed by negative returns, indicating these transactions are driven by negative information about the firm.     

Short-term residual reversal

Conventional short-term reversal strategies exhibit dynamic exposures to the Fama and French (1993) factors. We develop a novel reversal strategy based on residual stock returns that does not exhibit these exposures and consequently earns risk-adjusted returns that are twice as large as those of a conventional reversal strategy. Residual reversal strategies generate statistically and economically significant profits net of trading costs, even when we restrict our sample to large-cap stocks over the post-1990 period. Our results are inconsistent with the notion that reversal effects are the result of trading frictions or non-synchronous trading of stocks and pose a serious challenge to rational asset pricing models.     

Insider trading patterns

We revisit the information content of stock trading by corporate insiders with an expectation that opportunistic insiders will spread their trades over longer periods of time when they have a longer-lived informational advantage, and trade in a short window of time when their advantage is fleeting. Controlling for the duration of insiders' trading strategies, we find robust new evidence that both insiders' sales and purchases predict abnormal stock returns. In addition, we provide evidence that insiders attempt to preserve their informational advantages and increase their trading profits by disclosing their trades after the market has closed. When insiders report their trades after business hours, they are more likely to engage in longer series of trades, they trade more shares overall, and their trades are associated with larger abnormal returns. Finally, we show how accounting for these trading patterns sharpens screens for corporate insiders who trade on infor- mation.     

Female insiders' ethics and trading profitability

We provide the evidence of ethical differences between female and male top managers and insiders in conducting profitable trades with their own company stocks. Using a large sample of Chinese insider trading activities, we find that female insiders trade less profitably, which can be attributed to their higher ethical values. This relationship is robust for various profitability measures and holds after addressing potential endogeneity bias. We also provide evidence that our findings are not explained by female insiders' informational disadvantage, risk aversion, managerial ability, trading experience or concerns for differential legal consequences. Our study provides a more direct evidence on the ethical differences in gender in the context of insider trading.     

Expected Mispricing: The Joint Influence of Accounting Transparency and Investor Base

We examine how accounting transparency and investor base jointly affect financial analysts' expectations of mispricing (i.e., expectations of stock price deviations from fundamental value). Within a range of transparency, these two factors interactively amplify analysts' expectations of mispricing—analysts expect a larger positive deviation when a firm's disclosures more transparently reveal income‐increasing earnings management and the firm's most important investors are described as transient institutional investors with a shorter‐term horizon (low concentration in holdings, high portfolio turnover, and frequent momentum trading) rather than dedicated institutional investors with a longer‐term horizon (high concentration in holdings, low portfolio turnover, and little momentum trading). Results are consistent with analysts anticipating that transient institutional investors are more likely than dedicated institutional investors to adjust their trading strategies for near‐term factors affecting stock mispricings. Our theory and findings extend the accounting disclosure literature by identifying a boundary condition to the common supposition that disclosure transparency necessarily mitigates expected mispricing, and by providing evidence that analysts' pricing judgments are influenced by their anticipation of different investors' reactions to firm disclosures.     

High frequency momentum trading with cryptocurrencies

Over the past few years, cryptocurrencies have increasingly been discussed as alternatives to traditional fiat currencies. These digital currencies have garnered significant interest from investment banks and portfolio managers as a potential option to diversify the financial risk from investing in other assets. This interest has also extended to the general public who have seen cryptocurrencies as a way of making a quick profit. This paper provides a first insight into the applicability of high frequency momentum trading strategies for cryptocurrencies. We implemented two variations of a signal-based momentum trading strategy: (i) a time series method; (ii) a cross sectional method. These strategies were tested on a selection of seven of the largest cryptocurrencies ranked by market capitalization. The results show that there exists potential for the momentum strategy to be used successfully for cryptocurrency trading in a high frequency setting. A comparison with a passive portfolio strategy is proposed, which shows abnormal returns when compared with the momentum strategies. Furthermore, the robustness of our results are checked through the application of the momentum strategies other sample periods. We also compare the performances of the signal-based momentum strategies with returns-based versions of the strategies. It is shown that the signal-based strategy outperforms the returns-based strategy. However, there appears to be no single parameterization of the signal-based strategies that can generate the greatest cumulative return over all sample periods.     

Are investors consistent in their trading strategies? An examination of individual investor-level data

While it has been demonstrated that momentum or contrarian trading strategies can be profitable in a range of institutional settings, less evidence is available concerning the actual trading strategies investors adopt. Standard definitions of momentum or contrarian trading strategies imply that a given investor applies the same strategy to both their buy and sell trades, which need not be the case. Using investor-level, transaction-based data from China, where tax effects are neutral, we examine investors' buy-sell decisions separately to investigate how past returns impact differentially on the trading strategies investors adopt when buying and selling stock. After controlling for a wide range of stock characteristics, extreme price changes and portfolio value, a clear asymmetry in trading is observed; with investors displaying momentum behavior when buying stocks, but contrarian behavior when selling stocks. This asymmetry in behavior is not driven purely by reactions to stock characteristics or extreme stocks. We discuss behavioral and cultural explanations for our findings.     

A new strategy using term-structure dynamics of commodity futures

The term structure of commodity futures is important information for traders and investors. Traditional term-structure strategies are static; they tend to use the slope of term structure at a given moment. Instead, our trading strategy uses the change of term structure and generates statistically significant return. It also produces significant abnormal return in excess of the traditional two factors, i.e. the returns from static-slope strategy and daily momentum. Thus, its return includes orthogonal information or excess return that standard static-slope and momentum strategies cannot explain. This suggests a novel risk factor in the asset class of commodity futures or robust trading opportunities.     

Information Content of Insider Trading Around Corporate Announcements: The Case of Capital Expenditures

There is gathering evidence of insider trading around corporate announcements of dividends, capital expenditures, equity issues and repurchases, and other capital structure changes. Although signaling models have been used to explain the price reaction of these announcements, a usual assumption made in these models is that insiders cannot trade to gain from such announcements. An innovative feature of this paper is to model trading by corporate insiders (subject to disclosure regulation) as one of the signals. Detailed testable predictions are described for the interaction of corporate announcements and concurrent insider trading. In particular, such interaction is shown to depend crucially on whether the firm is a growth firm, a mature firm, or a declining firm. Empirical proxies for firm technology are developed based on measures of growth and Tobin's q ratio. In the underlying “efficient” signaling equilibrium, investment announcements and net insider trading convey private information of insiders to the market at least cost. The paper also addresses issues of deriving intertemporal announcement effects from the equilibrium (cross-sectional) pricing functional. Other announcement effects relate the intensity of the market response to insider trading, variance of firm cash flows, risk aversion of the insiders, and characteristics of firm technology (growth, mature, or declining).     

Losing sight of the trees for the forest? Attention allocation and anomalies

This paper tests asset pricing implications of the investor attention shift hypothesis proposed in theoretical work. We create a novel proxy for the dynamics of inattention towards firm-specific information and explore its impact on prominent return anomalies. As hypothesized and with all else equal, the proxy positively predicts the post-earnings announcement drift as well as the profitability of pairs trading, and negatively predicts the success of momentum strategies. Taken together, our findings highlight the importance of time-varying investor attention allocation for the price discovery process.     

Tax noncompliance and insider trading

This paper explores whether insiders who have shown noncompliance with the tax law (‘noncompliant insiders’) are more prone to exploit their information advantage in insider trading, compared to other insiders (‘compliant insiders’). Our empirical results from analyzing archival data of all insider trades in Sweden show that noncompliant insiders use more of their information advantage to trade their insider stocks shortly before significant stock price changes, compared to compliant insiders. These results remain similar after controlling for various insider- and firm-specific determinants of insider returns, including firm and year fixed effects. We believe that our results are of interest for academics and regulatory authorities monitoring and screening insider trading activity.     

Financial Transaction Taxes,Market Composition,and Liquidity

We use the introduction of a financial transaction tax (FTT) in France in 2012 to test competing theories on its impact. We find no support for the idea that an FTT improves market quality by affecting the composition of trading volume. Instead, our results are in line with the hypothesis that a lower trading volume reduces liquidity and in turn market quality. Consistent with theories of asset pricing under transaction costs, we document a shift in security holdings from short‐term to long‐term investors. Finally, we find that moderate aggregate effects on market quality can mask large adjustments made by individual agents.     

Insider trading in takeover targets

We examine open market stock trades by registered insiders in about 3700 targets of takeovers announced during 1988–2006 and in a control sample of non-targets, both during an ‘informed’ and a control period. Using difference-in-differences regressions of several insider trading measures, we find no evidence that insiders increase their purchases before takeover announcements; instead, they decrease them. But while insiders reduce their purchases below normal levels, they reduce their sales even more, thus increasing their net purchases. This ‘passive’ insider trading holds for each of the five insider groups we examine, for all three measures of net purchases, and is more pronounced in certain sub-samples with less uncertainty about takeover completion, such as friendly deals, and deals with a single bidder, domestic acquirer, or less regulated target. The magnitude of the increase in the dollar value of net purchases is quite substantial, about 50% relative to their usual levels, for targets' officers and directors in the six-month pre-announcement period. Our finding of widespread profitable passive trading by target insiders during takeover negotiations points to the limits of insider trading regulation. Finally, our finding that registered insiders of target firms largely refrain from profitable active trading before takeover announcements contrasts with prior findings that insiders engage in such trading before announcements of other important corporate events, and points to the effectiveness of private over public enforcement of insider trading regulations.     

IQ and corporate insiders’ decisions to time insider and outsider trading

We examine how corporate insiders’ cognitive ability (IQ) affects their decisions to time insider and outsider trading before abnormal stock price changes. Our analysis of archival data on male corporate insiders in Sweden shows they are less prone to time their insider selling and to sell in larger amounts, before abnormal stock price declines as IQ increases. We also find that insiders with a higher IQ are better at timing their outsider buying. Taken together, our results show that corporate insiders’ IQ affects their trading decisions differently, depending on whether they are trading in their insider or outsider stocks.     

Insider Trading and Corporate Information Transparency

Our study examines the relation between insider trading and corporate information transparency. We find a negative relation between firms’ information transparency and the economic significance of insider trading, including the amount of insider purchase and sale and the profitability of insider transactions. We also find a negative relation between information transparency and stock price reaction to news of insider trading, which suggests that increases in information transparency preempt insiders’ private information. Our study provides evidence consistent with firms’ transparency-enhancing activities decreasing information asymmetry between insiders and investors by revealing insiders’ private information to investors in a timely manner.     

Strategic insider trading: Disguising order flows to escape trading competition

Short sellers actively exploit trading opportunities from insider sales. We argue that, in response to concern about potential order flow information leakage, insiders strategically disguise their order flows to escape trading competition. Our model predicts that, when short sellers are sensitive to order flow information, insiders are more likely to adopt a cautious trading strategy, i.e., splitting their trades over time. Empirically, we identify cautious trading by tracking consecutive transactions at the insider-strategy level. We find that, when anticipating intensive short selling potential, (1) insiders tend to trade cautiously; and (2) cautious insiders tend to reduce their initial trades. Overall, we highlight the strategic interaction between insiders and short sellers on the diffusion of order flow information.     

卖空机制能够约束内部人减持吗？——基于融资融券制度的经验证据

本文以我国放松卖空管制为视角,探究其对内部人减持的影响。研究表明,卖空机制能够抑制企业内部人减持行为。机制分析发现,卖空对内部人减持的抑制作用是通过缓解股权高溢价实现的。进一步研究表明,卖空能够抑制大股东、董事以及管理层减持,但对监事减持无影响;卖空能够降低内部人减持的获利程度,并且在内部人减持动机更大时,对内部人减持的抑制作用更强;卖空通过约束内部人减持提升了股票定价效率,还有助于降低内部人增持行为。本文的研究结论丰富了卖空和内部人减持领域的文献,并对政府部门完善制度设计具有启示意义。