短期动量效应与收益反转效应研究——基于中国中小板市场数据实证分析

依据2011年中小板市场股票的日收益率考量对该市场短期动量效应与反转效应。结果显示:当形成期为一周时,持有期为一周、四周、八周的情况下市场均存在收益反转现象;当形成期为两周时,持有期为四周、八周的情况下市场均存在收益反转现象;当形成期为四周、八周时,各种持有期情况下均存在反转效应。重叠抽样结果显示:除了形成期为两周且持有期为两周的情况下,市场效应不明显之外,其他均显著表现为收益反转效应。同时采用静态与动态的投资策略验证2012年上半年的数据,发现时间段的选取对于研究结论有显著的影响;动态投资策略能够实现更为可观的收益,但收益波动也更为剧烈。     

Australian momentum: performance,capacity and the GFC effect

This paper assesses the performance of momentum strategies in Australia, and how they were affected by the GFC. This paper is the first to address the issue of the dollar capacity of momentum strategies in the Australian market. We find evidence of a strong momentum effect in Australia amongst the S&P/ASX200 constituents. We find that momentum portfolios suffered during the GFC, but the effect was not persistent. Finally, we show that the capacity of the momentum effect in Australia is large enough in dollar terms to reject the assertion that momentum is more of a theoretical than a practical construct.     

Price gap anomaly in the US stock market: The whole story

This paper analyses the price gap anomaly in the US stock market (comprised of the DJI, S&P 500 and NASDAQ) covering the period 1928 to 2018. This paper aims to investigate whether or not price gaps create market inefficiencies. Price gaps occur when the current day’s opening price is different from the previous day’s closing price due orders placed before the opening of the market. Several hypotheses are tested using various statistical tests (Student’s t-test, ANOVA, Mann-Whitney test), regression analysis, and special methods, that is, the modified cumulative returns and the trading simulation approaches. We find strong evidence in favour of abnormal price movements after price gaps. We observe that during a gap day prices tend to change in the direction of the gap. A trading strategy based on this anomaly was efficient in that its results were not random, indicating that this market was not efficient. The momentum effect was found to be temporary and no evidence of seasonality in price gaps was found. Lastly, our results were also contrary to the myth that price gaps tend to get filled.     

Horse race of weekly idiosyncratic momentum strategies with respect to various risk metrics: Evidence from the Chinese stock market

This paper focuses on the horse race of weekly idiosyncratic momentum (IMOM) with respect to various idiosyncratic risk metrics. Using the A-share individual stocks in the Chinese market from January 1997 to December 2017, we first evaluate the performance of the weekly momentum based on raw returns and idiosyncratic returns, respectively. After that the univariate portfolio analysis is conducted to investigate the return predictability with respect to various idiosyncratic risk metrics. Further, we perform a comparative study on the performance of the IMOM portfolios with respect to various risk metrics. At last, we explore the possible explanations to IMOM as well as risk-based IMOM portfolios. We find that 1) there are prevailing contrarian effect and IMOM effect for the whole sample; 2) the negative relations exist between most of the idiosyncratic risk metrics and the cross-sectional stock returns, and better performance is linked to idiosyncratic volatility (IVol) and maximum drawdowns (IMDs); 3) additionally, the IVol-based and IMD-based IMOM portfolios exhibit better explanatory power to the IMOM portfolios with respect to other risk metrics; 4) finally, higher profitability of IMOM as well as IVol-based and IMD-based IMOM portfolios is found to be related to upside market states, high levels of liquidity and high levels of investor sentiment.     

Momentum and betting market perceptions of momentum in college football

Past research has demonstrated that bettors believe positive momentum carries over from contest to contest. This article examines whether there is any empirical support for this belief by testing for the presence of across-contest momentum effects in college football. We characterize momentum in multiple fashions and after controlling for between-team heterogeneity find no evidence that systematic relationships exist between the degree of momentum a team enters a contest with and the outcome of that contest. From a wagering market perspective, this indicates that there is no statistically significant advantage to betting on teams perceived to possess positive momentum. Our results also suggest that the combination of the opening betting line set by odds makers and the subsequent market movement of that line does not systematically overreact to teams on streaks.     

动量和反转投资策略理论研究

本文分析了EMH和行为金融理论指导下不同的投资策略,重点对基于反应不足和反应过度的动量和反转投资策略的国内外相关研究状况进行了描述。     

A new assessment of economic integration in East Asia: Application of an industry-specific G-PPP model

It is well known that intra-industry trade and cross-border production networks have promoted economic growth and regional integration in East Asia. However, regional supply and production chains may have been formed differently across industries, reflecting different degrees and a different scope of regional economic linkages at an industry level. This paper makes a threefold contribution. First, to assess industry-level differences, this study adopts the generalized purchasing power parity (G-PPP) model using industry-specific producer prices. Second, the momentum threshold autoregressive (M-TAR) model is employed to allow for possible nonlinearity arising from the dynamic nature of regional economic growth and development. Third, the Granger causality test is also conducted to assess whether regional economies have autonomously integrated. The empirical results reveal that economic integration has progressed more autonomously in the electrical industry, as well as in the transportation equipment industry, as China and the ASEAN countries have become the final destination markets for finished products in these two industries.     

Insider trading,growth opportunities and the market reaction to new financing announcements*

Abstract

This paper explores the profitability of momentum strategies, by investigating if a momentum strategy is superior to a benchmark model once the effects of data-snooping have been accounted for. Two data sets are considered. The first set of data consists of US stocks and the second one consists of Swedish stocks. For the US data strong evidence is found of a momentum effect and hence the hypothesis of weak market efficiency is rejected. Splitting the sample in two parts, it is found that the overall significance is driven by events in the earlier part of the sample. The results for the Swedish data indicate that momentum strategies based on individual stocks generate significant profits. A very weak or no momentum effect can be found when stocks are sorted into portfolios. Finally, and perhaps most importantly, results show that data-snooping bias can be very substantial. Neglecting the problem would lead to very different conclusions.     

The momentum and reversal effects of investor sentiment on stock prices

In this paper, we illustrate the real function relationship between the stock returns and change of investor sentiment based on the nonparametric regression model. The empirical results show that when the change of investor sentiment is moderate, the stock return is positively correlated with the change of investor sentiment, presenting an obvious momentum effect. However, the stock return is negatively correlated with the change of investor sentiment if the change of investor sentiment is dramatic, presenting significant reversal effects. Moreover, the degree of reversal effect caused by extremely optimistic sentiment is greater than that driven by extremely pessimistic sentiment, which shows a significant asymmetry. Our findings offer a partial explanation for financial anomalies such as the mean reversion of stock returns, the characteristic of slow rise and steep fall in China's stock market and so on.     

Modelling the behaviour of the new issue market

This paper analyses the time series behaviour of the initial public offering (IPO) market using an equilibrium model of demand and supply that incorporates the number of new issues, average underpricing, and general market conditions. Model predictions include the existence of serial correlation in both the number of new issues and the average level of underpricing, as well as interactions between these variables and the impact of general market conditions. The model is tested using 40 years of monthly IPO data. The empirical results are generally consistent with predictions.