Reward-risk momentum strategies using classical tempered stable distribution

We implement momentum strategies using reward-risk measures as ranking criteria based on classical tempered stable distribution. Performances and risk characteristics for the alternative portfolios are obtained in various asset classes and markets. The reward-risk momentum strategies with lower volatility levels outperform the traditional momentum strategy regardless of asset class and market. Additionally, the alternative portfolios are not only less riskier in risk measures such as VaR, CVaR and maximum drawdown but also characterized by thinner downside tails. Similar patterns in performance and risk profile are also found at the level of each ranking basket in the reward-risk portfolios. Higher factor-neutral returns achieved by the reward-risk momentum strategies are statistically significant and large portions of the performances are not explained by the Carhart four-factor model.     

基于牛市和熊市不同周期的股票市场动量效应研究

在参考国外研究方法的基础上,以周作为检验周期,将1997年6月至2001年6月的股市作为牛市,2001年6月至2005年6月的股市作为熊市,然后分别检验股市在这两个不同时期的动量效应.研究发现,赢家组合在牛市中存在着正的动量效应,输家组合在熊市中存在着负的动量效应.而牛市中的输家组合和熊市中的赢家组合都存在着价格的反转.     

Predictability of future index returns based on the 52-week high strategy

In a landmark paper, George and Hwang (2004) show that a stock's 52-week high price largely explains the momentum effect and that a strategy based on closeness to the 52-week high has better forecasting power for future returns than do momentum strategies. We find that the 52-week high strategy is unprofitable when applied to emerging markets indices, and that it is significantly less profitable than the corresponding momentum strategy. Overall the 52-week high effect is not as pervasive as the momentum effect.     

Recent evidence on the short-term and long-term performance persistence of emerging-market mutual fund returns

This paper analyzes the performance persistence of US-based emerging-market mutual funds. We use a sample of 275 actively managed funds between July 1989 and December 2020 and regress their returns on emerging-market benchmark portfolios. On average, the funds had a significant negative alpha. Contrary to some earlier evidence, we document that the short-term consistency is entirely driven by losses of underperforming funds. The return spread between the short-term winners and losers generates a significant positive alpha that can be fully explained by the momentum in emerging-market stocks. We find no evidence of any long-term regularities. Our findings show that the observed funds exhibit very similar behavior to their developed-market counterparts and may contribute to resolving some inconsistencies in the earlier results.     

Forecasting,uncertainty and risk; perspectives on clinical decision-making in preventive and curative medicine

Should we screen the population routinely for the presence of breast or prostatic cancer? This simple proposition masks a landscape of complexities, including the economics of screening, the prevalence and probability of the disease, desired frequencies of intervention and a willingness to adopt preventive screening. These ‘risk factors’ form part of a broader landscape of uncertainty that characterises the intricacies of clinical decision-making. Deepening our understanding of the way in which clinicians evaluate risk and uncertainty requires a framing of insights into language, communication, psychology and epistemology. This paper explores perspectives in forecasting and uncertainty as a basis for understanding individuals’ perceptions of risk when assessing their options in both preventative and curative medicine. At the heart of the issue is the prevalence of diagnostic error; this paper argues for the use of systematised approaches to medical error management and inclusive approaches to research in the field. The advantages of augmenting the management of unforeseen consequences through an improved understanding of the issues that are of concern to patients, carers, and medical practitioners alike forms a key construct in this paper. We conclude with an exploration of potential opportunities for improvements in medical practice: changes that may reduce the disbenefits of uncertainty and enhance the management of the general risks associated with clinical decision-making.     

The evolvement of momentum effects in China: Evidence from functional data analysis

Using an approach based on functional data analysis, we address the controversy that momentum or reversal effect disputes exist in China’s A-shares markets. It finds patterns of nonlinear cross-sectional variation and the dynamic change of average stock returns over time. After the global financial crisis of 2008, our empirical results show that momentum effects in the middle term went away and reversal effects took over. We also find substantial reversal effects for the short- (1-6 months) and long-term (3 years), respectively, but no evidence of permanent momentum effects in China.     

Re-examining differences between momentum and time series momentum among individual stocks

In this paper, we provide a comprehensive comparison of momentum (CSMOM) and time series momentum (TSMOM) among individual stocks in the US stock market from January 1964 to December 2015 and find that the two are distinct among individual stocks. With zero-cost strategies on both of them, we find that the explanations in Goyal and Jegadeesh (2018) cannot fully explain the differences between the performances of CSMOM strategies and TSMOM strategies.     

区域科技金融生态系统共生与进化实证研究

基于生态学理论和金融共生理论,分析区域科技金融生态系统内生态种群共生关系及共生效应,以2010—2018年中国（内地）31个省域为研究对象,运用共生度测度模型和融合速度特征的共生进化动量模型,测度区域科技金融生态系统共生水平与共生进化动量。实证结果表明,东部地区在考察期内科技金融生态系统的共生度较高,但其共生进化呈疲软甚至恶化态势。相较而言,虽然中西部地区在考察期内科技金融生态系统共生度较低,但其共生进化呈良性上升态势。据此,提出强化区域科技金融生态系统共生与共生进化动量的对策建议。     

Hyperbolic discounting and the standard model: Eliciting discount functions

Experiments on static intertemporal choice find evidence of particularly extreme impatience toward immediate rewards. While this is often taken as support for hyperbolic discounting, it could also arise because the most likely participants in experiments may be those with the most immediate need for money. We conduct a calibration exercise and find that the extreme impatience observed in experiments can be accommodated by a standard exponential discounting model with no discounting and expectation of a ‘small’ increase in the base consumption level. The calibration uses existing estimates of curvature of utility.     

Can monthly-return rank order reveal a hidden dimension of momentum? The post-cost evidence from the U.S. stock markets

We introduce a new return-momentum indicator that is based on monotonicity of monthly-return rank order within a lookback period (henceforth abbreviated as MRRO). Based on an extensive post-cost performance comparison of long-only momentum portfolios formed on six stand-alone and 36 double-sort criteria across three holding period lengths in the non-microcap universe of U.S. stocks over the 55-year sample period, MRRO is particularly useful for annual holding periods, towards the end of whom the conventional return-momentum indicators tend to lose their prediction power. Based on the return-based style analysis, MRRO adds some favorable style-diversification characteristics into long-only momentum portfolio selection.