Realizing stock market crashes: stochastic cusp catastrophe model of returns under time-varying volatility

This paper develops a two-step estimation methodology that allows us to apply catastrophe theory to stock market returns with time-varying volatility and to model stock market crashes. In the first step, we utilize high-frequency data to estimate daily realized volatility from returns. Then, we use stochastic cusp catastrophe theory on data normalized by the estimated volatility in the second step to study possible discontinuities in the markets. We support our methodology through simulations in which we discuss the importance of stochastic noise and volatility in a deterministic cusp catastrophe model. The methodology is empirically tested on nearly 27 years of US stock market returns covering several important recessions and crisis periods. While we find that the stock markets showed signs of bifurcation in the first half of the period, catastrophe theory was not able to confirm this behaviour in the second half. Translating the results, we find that the US stock market’s downturns were more likely to be driven by the endogenous market forces during the first half of the studied period, while during the second half of the period, exogenous forces seem to be driving the market’s instability. The results suggest that the proposed methodology provides an important shift in the application of catastrophe theory to stock markets.     

Are stock prices related to the political uncertainty index in OECD countries? Evidence from the bootstrap panel causality test

This study applies the bootstrap panel causality test proposed by Kónya (2006. Econ Modell 23, 978) to investigate the causal link between political uncertainty and stock prices for seven OECD countries over the monthly period of 2001.01 to 2013.04. This modeling approach allows us to examine both cross-sectional dependency and country-specific heterogeneity. Our empirical results indicate that not all the countries are alike and that the theoretical prediction that stock prices fall at the announcement of a policy change is not always supported. Specifically, we find evidence for the stock price leading hypothesis for Italy and Spain, while the political uncertainty leading hypothesis cannot be rejected for the United Kingdom and the United States. In addition, the neutrality hypothesis was supported in the remaining three countries (Canada, France and Germany), while no evidence for the feedback hypothesis was found.     

Position limit for the CSI 300 stock index futures market

The aim of this study was to find the optimal position limit for the Chinese stock index (CSI) 300 futures market. A low position limit helps to prevent price manipulations in the spot market, and thus keeps the magnitude of instantaneous price changes within the tolerance range of policymakers. However, setting a position limit that is too low may also have negative effects on market quality. We propose an artificial limit order market with heterogeneous interacting agents to examine the impact of different levels of position limits on market quality, measured as liquidity, return volatility, efficiency of information dissemination, and trading welfare. The simulation model is based on realistic trading mechanisms, investor structure, and order submission behavior observed in the CSI 300 futures market.Our results show that on the basis of the liquidity status in September 2010, raising the position limit from 100 to 300 could significantly improve market quality and at the same time keep the maximum absolute price change per 5 s below the 2% tolerance level. However, the improvement becomes only marginal if the position limit is further increased beyond 300. Therefore, we believe that raising the position limit to a moderate level can enhance the functionality of the CSI 300 futures market, which should benefit the development of the Chinese financial system.     

交易者关注行为对股票价格的影响机制

本文研究了交易者的关注行为对股票价格的影响机制。通过控制了公司基本面的因素基础上,分别从最终量（股票价格）和变化量（价格差）两个角度,建立了影响模型,实证发现,无论是最终量还是变化量,当期的关注度产生的正向响应都是强于滞后一期产生的反向影响;进一步用格兰杰因果分析了两者的关系,发现互为双向格兰杰原因;通过脉冲响应了解相互之间作用的模式,发现关注度对价格短期内是反向波动的影响,长期会有正向的响应。     

Should we worry about the decline of the public corporation? A brief survey of the economics and external effects of the stock market

In recent years, the number of listed companies has been declining in many countries across the world. This paper provides a selective survey of the literature on the real economic effects of the stock market to assess the potential effects of this decline and determine whether it is likely to continue. The leading economic role of the stock market’s primary market, in which firms raise capital by issuing new shares, is to help growing firms secure financing. We discuss providing and certifying information, coordinating investors, and easing the redeployment of capital as the means through which capital allocation can be efficiently achieved. The main economic roles of the stock market’s secondary market, the trade in existing shares, is to provide liquidity to shareholders, to aid in price discovery and to provide diversification opportunities. Positive external effects from an active stock market may arise for consumers, labor and private firms due to increased corporate investment, more socially responsible business strategies and a more positive business climate. Negative external effects on capital allocation and productivity can arise from short-termism, market mispricing, and increased cross-ownership. Local stock markets can spur innovation and foreign direct investment (FDI) and reduce the risk of early cross-border acquisitions. Given the myriad of useful economic functions the stock market performs, a future entirely absent of public companies is difficult to imagine and the decline is therefore likely at some point to come to an end. Whether we need to worry about the decline depends on the relative importance of the positive and negative external effects, a topic we feel warrants more research.     

Are stock markets really so inefficient? The case of the “Halloween Indicator”

The old and simple investment strategy “Sell in May and Go Away” (also referred to as the “Halloween effect”) enjoys an unbroken popularity. Recent studies suggest that the Halloween effect even strengthened rather than weakened since its first publication by Bouman and Jacobsen (2002). We implement regression models as well as Hansen’s (2005) “Superior Predictive Ability” test to analyze whether stock markets are really so inefficient. In line with the predictions of market efficiency, our results reject the hypothesis that a trading strategy based on the Halloween effect significantly outperforms.     

HOW DO RATING AGENCIES’ DECISIONS IMPACT STOCK MARKETS? A META‐ANALYSIS

The purpose of this study is to examine how credit rating agencies’ decisions impact the stock market using a systematic and quantitative review of existing empirical studies. Specifically, we employ a meta‐regression analysis (MRA) to investigate the extent and nature of the effect of rating agencies’ decisions on the stock market. We survey 62 studies published between 1978 and 2015. Our first finding is that the cumulative average abnormal returns calculated from this empirical literature are affected by publication bias. After controlling for publication bias, the main findings of our meta‐analysis indicate that negative rating decisions cause statistically significant negative abnormal returns. This evidence suggests an informational effect. Our results also indicate that positive rating decisions do not have a significant effect. Finally, the MRA results reveal the importance of several factors related to primary study design, as well as to the nature of the data.     

Investment horizons,cash flow news,and the profitability of momentum and reversal strategies in the Chinese stock market

This study investigates the profitability of momentum and reversal strategies of different investment horizons in the Chinese stock market. The findings indicate that momentum strategies are profitable for investment horizons less than one week. For longer investment horizons, reversal strategies are profitable. This result is very different from the US market, where profitable momentum strategies yield to much longer investment horizons. We show that this is because investors in Chinese stock market generally overreact to the company cash flow news while investors in US market underreact to cash flow news.