Momentum, Business Cycle, and Time-varying Expected Returns

A growing number of researchers argue that time-series patterns in returns are due to investor irrationality and thus can be translated into abnormal profits. Continuation of short-term returns or momentum is one such pattern that has defied any rational explanation and is at odds with market efficiency. This paper shows that profits to momentum strategies can be explained by a set of lagged macroeconomic variables and payoffs to momentum strategies disappear once stock returns are adjusted for their predictability based on these macroeconomic variables. Our results provide a possible role for time-varying expected returns as an explanation for momentum payoffs.     

Return dispersion risk in FX and global equity markets: Does it explain currency momentum?

We investigate the potential link between momentum in currency returns and global economic risk as measured by currency return dispersion (RD). Initial tests contribute to the exchange rate puzzle by showing that a common macroeconomic risk component in currency markets is present in global equity markets. Subsequent tests indicate that the spread on zero-cost currency momentum strategies is larger and highly significant in high RD states compared to low RD states. Also, the relation between these momentum payoffs and global economic risk appears to increase linearly in risk. Based on this evidence, we conclude that global economic risk as proxied by RD helps to explain currency momentum profits.     

Market States and Momentum

We test overreaction theories of short-run momentum and long-run reversal in the cross section of stock returns. Momentum profits depend on the state of the market, as predicted. From 1929 to 1995, the mean monthly momentum profit following positive market returns is 0.93%, whereas the mean profit following negative market returns is −0.37%. The up-market momentum reverses in the long-run. Our results are robust to the conditioning information in macroeconomic factors. Moreover, we find that macroeconomic factors are unable to explain momentum profits after simple methodological adjustments to take account of microstructure concerns.     

Has momentum lost its momentum?

We evaluate the robustness of momentum returns in the US stock market over the period 1965–2012. We find that momentum profits have become insignificant since the late 1990s. Investigations of momentum profits in high and low volatility months address the concerns about unprecedented levels of market volatility in this period rendering momentum strategy unprofitable. Momentum profits remain insignificant in tests designed to control for seasonality, up or down market conditions, firm size and liquidity. Past returns, can no longer explain the cross-sectional variation in stock returns, even following up markets. Investigation of post holding period returns of momentum portfolios and risk adjusted buy and hold returns of stocks in momentum suggests that investors possibly recognize that momentum strategy is profitable and trade in ways that arbitrage away such profits. These findings are partially consistent with Schwert (Handbook of the economics of finance. Elsevier, Amsterdam, 2003) that documents two primary reasons for the disappearance of an anomaly in the behavior of asset prices, first, sample selection bias, and second, uncovering of anomaly by investors who trade in the assets to arbitrage it away. In further analyses we find evidence that suggest two other possible explanations for the declining momentum profits, besides uncovering of the anomaly by investors, that involve decline in the risk premium on a macroeconomic factor, growth rate in industrial production in particular and relative improvement in market efficiency.     

Momentum strategies: some bootstrap tests

This study introduces a new estimation-based bootstrap simulation procedure to test whether different returns-generating models can explain the profitability of momentum strategies first documented by Jegadeesh and Titman [J. Finance 48 (1993)]. We incorporate simple random walk and multifactor models and allow for autocorrelation, cross-correlation, conditional heteroskedasticity and predictability through conditioning information variables. We also evaluate alternative sampling procedures for the bootstrap simulations. None of the models, however, are able to generate simulated profits as large as the actual profits. We do find, however, that accounting for time-varying expected returns with market-wide and macroeconomic instrumental variables can explain 75–80% of the profits.     

International price and earnings momentum

In this paper, we find that price and earnings momentum are pervasive features of international equity markets even when controlling for data-snooping biases. For Europe, we show price momentum to be subsumed by earnings momentum on an aggregate level. However, this rationale can hardly be sustained on a country level. Also, the above explanation is confined to certain time periods in the USA. Since we cannot establish a decent relation between momentum and macroeconomic risks, we suspect a behavior-based explanation to be at work. In fact, we find momentum profits to be more pronounced for portfolios characterized by higher information uncertainty. Hence, the momentum anomaly may well be rationalized in a model of investors underreacting to fundamental news. Finally, we find that momentum works better when limited to stocks with high idiosyncratic risk or higher illiquidity, suggesting that limits to arbitrage deter rational investors from exploiting the anomaly.     

The 52-week high momentum strategy in international stock markets

We study the 52-week high momentum strategy in international stock markets proposed by George and Hwang [George, T., Hwang, C.Y., 2004. The 52-week high and momentum investing. Journal of Finance 59, 2145-2176.]. This strategy produces profits in 18 of the 20 markets studied, and the profits are significant in 10 markets. The 52-week high momentum profits exist independently from the Jegadeesh and Titman [Jegadeesh, N., Titman, S., 1993. Returns to buying winners and selling losers: implications for market efficiency. Journal of Finance 48, 65-91.] individual stock and Moskowitz and Grinblatt [Moskowitz, T.J., Grinblatt, M., 1999. Do industries explain momentum? Journal of Finance 54, 1249-1290] industry momentum strategies. These profits do not show reversals in the long run. We find that the 52-week high is a better predictor of future returns than macroeconomic risk factors or the acquisition price. The individualism index, a proxy to the level of overconfidence, has no explanatory power to the variations of the 52-week high momentum profits across different markets. However, the profits are no longer significant in most markets once transaction costs are taken into account.     

Sources of momentum profits in international stock markets

This paper examines the sources of momentum profits of countries exhibiting and not exhibiting momentum and compares the differences in the underlying factors determining momentum profits between these two groups of countries. We find remarkable differences in the decomposed components between these two groups of countries. Countries exhibiting momentum show that the cross‐sectional dispersion in unconditional mean returns dominates the negative contribution from the component reflecting the intertemporal behaviour of asset returns. However, this is not the case in countries exhibiting no momentum. Furthermore, countries with greater relative contribution from the cross‐sectional variance in unconditional mean returns tend to have greater momentum profits. Our results may support risk‐based explanations for the momentum phenomenon rather than behavioural finance‐based explanations.     

Profitability of momentum strategies in international markets: The role of business cycle variables and behavioural biases

The paper investigates whether business cycle variables and behavioural biases can explain the profitability of momentum trading in three major European markets. Unlike previous studies, the paper nests both risk-based and behavioural-based variables in a two-stage model specification in an attempt to explain momentum profits. The findings show that, although momentum profitability in European markets is unexplained by conditional asset pricing models, it is attributable to asset mispricing that systematically varies with global business conditions. In addition, behavioural variables do not appear to matter much. Thus risk factors, which are undetected thus far and are largely attributable to the business cycle, could explain the momentum payoffs in European stock markets.     

Economic policy uncertainty and momentum

We show that a news‐based measure of economic policy uncertainty (EPU) negatively forecasts momentum. A 1‐standard‐deviation increase in EPU is associated with a 1.11% decrease in risk‐adjusted momentum returns. The predictive power of EPU is robust after controlling for previously documented economic state variables and macroeconomic uncertainty. We provide an explanation for these results from the perspective of a fund flow‐induced trading mechanism and offer direct empirical support. The literature documents that momentum can be partially attributed to performance‐chasing mutual fund flows. We find that this flow‐induced mechanism functions more effectively in low EPU states, thereby generating stronger stock momentum.     

Understanding the nature of the risks and the source of the rewards to momentum investing

Buying recent winners and shorting recent losers guaranteestime-varying factor exposures in accordance with the performanceof common risk factors during the ranking period. Adjusted forthis dynamic risk exposure, momentum profits are remarkablystable across subperiods of the entire post-1926 era. Factormodels can explain 95% of winner or loser return variability,but cannot explain their mean return components are more profitablethan those based on total returns. Neither industry effectsnor cross-sectional differences in expected returns are theprimary cause of the momentum phenomenon.     

Productivity Risk and Industry Momentum

A productivity shock identified through a vector autoregression model is a priced risk factor for one‐month industry momentum portfolios and commands a positive risk premium. Stocks in winning industries have greater sensitivity to productivity news, thereby earning higher average returns than stocks in losing industries. This evidence lends support to an Intertemporal Capital Asset Pricing Model (ICAPM) with human wealth. In many specifications, exposure to productivity risk captures more than half of the observed industry momentum profits. This paper studies the sources of profits and attributes the risks of industry momentum portfolios to the behavior of their underlying cash flows.     

Momentum,Reversals, and Fund Manager Overconfidence

This paper examines the role of investor overconfidence and self‐attribution bias in explaining the momentum effect. We develop a novel measure of overconfidence based on characteristics and trading patterns of US equity mutual fund managers. Stocks held by more overconfident managers experience greater momentum profits and stronger return reversals than stocks held by less overconfident managers. The difference in momentum profits is not compensation for risk nor is it attributable to stock characteristics that influence momentum. Our results are consistent with Daniel, Hirshleifer, and Subrahmanyam (1998) who argue that momentum results from delayed overreaction caused by overconfidence and biased self‐attribution.     

Macroeconomic risks and characteristic-based factor models

We show that book-to-market, size, and momentum capture cross-sectional variation in exposures to a broad set of macroeconomic factors identified in the prior literature as potentially important for pricing equities. The factors considered include innovations in economic growth expectations, inflation, the aggregate survival probability, the term structure of interest rates, and the exchange rate. Factor mimicking portfolios constructed on the basis of book-to-market, size, and momentum therefore, serve as proxy composite macroeconomic risk factors. Conditional and unconditional cross-sectional asset pricing tests indicate that most of the macroeconomic factors considered are priced. The performance of an asset pricing model based on the macroeconomic factors is comparable to the performance of the Fama and French (1993) model. However, the momentum factor is found to contain incremental information for asset pricing.     

Price Momentum and Idiosyncratic Volatility

We find that returns to momentum investing are higher among high idiosyncratic volatility ( IVol) stocks, especially high IVol losers. Higher IVol stocks also experience quicker and larger reversals. The findings are consistent with momentum profits being attributable to underreaction to firm‐specific information and with IVol limiting arbitrage of the momentum effect. We also find a positive time‐series relation between momentum returns and aggregate IVol. Given the long‐term rise in IVol, this result helps explain the persistence of momentum profits since Jegadeesh and Titman's (1993) study.     

Depositor Behavior under Macroeconomic Risk: Evidence from Bank Runs in Emerging Economies

Depositor behavior has been associated with bank‐specific characteristics, random runs, or contagion episodes. Using evidence on the 2000–02 bank runs in Argentina and Uruguay, this paper shows that macroeconomic risk is also important. Few macroeconomic shocks can quickly cause large runs. Macroeconomic risk affects deposits regardless of traditional bank‐specific characteristics. Furthermore, bank exposure to macroeconomic factors can explain differences in deposit withdrawals. During crises, the evolution of bank‐specific characteristics is mainly driven by macroeconomic factors, while the informational content of bank‐specific variables declines. Overall, depositors seem responsive to risk in a broader sense than that often considered by the literature.     

Is default risk the hidden factor in momentum returns? Some empirical results

This paper analyzes the role of default risk in the momentum effect focusing on data from four developed European stock markets (France, Germany, Spain and the United Kingdom). Using a market‐based measure of default risk, we show that it is not the hidden factor behind this effect. While the loser portfolio is characterized by high default risk, small size, high book‐to‐market and illiquidity, characterization of the winner portfolio is somewhat more complex. Given that the momentum strategy is the return differential between the winners and the losers, factors such as the stock market cycle or the evolution of momentum portfolios against their reference point make momentum profits difficult to forecast.     

Risk adjustment and momentum sources

We show that the conventional procedure of risk adjustment by running full-sample time-series Fama-French three-factor regressions is not appropriate for momentum portfolios because the procedure fails to allow for the systematic dynamics of momentum portfolio factor loadings. We propose a simple procedure to adjust risks associated with the Fama-French three factors for momentum portfolios. Using our proposed method, the Fama-French three factors can explain approximately 40% of momentum profits generated by individual stocks and nearly all of momentum returns from style portfolios.     

投资者非理性行为是动量效应产生的原因吗?——来自互联网金融论坛的证据

动量效应是行为金融研究中重要的市场异象,然而目前各市场因素并不能完全解释其来源。在大数据背景下,本文通过挖掘金融论坛的结构化和非结构化数据,深入研究投资者微观行为与动量效应的关系,发现市值规模、账面市值比和行业等市场因素仅能解释约30%的动量效应,而基于行为金融的投资者非理性因素——投资者情绪、投资者关注度和情绪传播度,都是动量效应形成的重要因素,在市场因素的基础上还能继续解释35%左右的动量效应。研究结论对理解动量效应的形成机制和投资实践中网络信息的价值有重要意义。     

The Profitability of Momentum Investing

We test for the presence of momentum profits in the UK over the period 1977 to 1998. The analysis shows that significant momentum profits are present in both a comprehensive sample of UK stocks and an accounting sub-sample. An analysis of sub-period results, seasonal effects, and the persistence of momentum profits confirms the robustness of the results. Controlling for factors known to be associated with differences in average returns, such as size, stock price, book-to-market ratio, and cash earnings-to-price ratio, cannot explain momentum profits. We also confirm that serial correlation in common factors and delayed price reaction to common factor realisations cannot explain momentum profits. We conclude that the momentum effect derives from market underreaction to either industry- or firm-specific information and it is a significant, independent phenomenon in UK stock returns.