The Comovement of US and UK Stock Markets

US and UK stock returns are highly positively correlated over the period 1918–99. Using VAR‐based variance decompositions, we investigate the nature of this comovement. Excess return innovations are decomposed into news about future dividends, real interest rates, and excess returns. We find that the latter news component is the most important in explaining stock return volatility in both the USA and the UK and that stock return news is highly correlated across countries. This is evidence against Beltratti and Shiller's (1993) finding that the comovement of US and UK stock markets can be explained in terms of a simple present value model. We interpret the comovement as indicating that equity premia in the two countries are hit by common real shocks.     

ROBUSTNESS OF THE HEADQUARTERS‐CITY EFFECT ON STOCK RETURNS

Recent studies report that U.S. firms headquartered near each other experience positive comovement in their stock returns, a finding suggestive of local biases in equity trading activity. We investigate the robustness of these findings and find that including additional pricing factors in models for monthly stock returns materially reduces the magnitude of the headquarters‐city effect in stock returns. Additionally, we find that an implicit null hypothesis of zero local return comovement is inappropriate as there is positive comovement between a stock's return and returns on portfolios of stocks from nonheadquarters cities, on average. Nevertheless, results benchmarked against estimates based on resampling methods indicate a significant and robust headquarters‐city effect in stock returns.     

The dark side of global integration: Increasing tail dependence

We measure stock market coexceedances using the methodology of Cappiello, Gerard and Manganelli (2005, ECB Working Paper 501). This method enables us to measure comovement at each point of the return distribution. First, we construct annual coexceedance probabilities for both lower and upper tail return quantiles using daily data from 1974–2006. Next, we explain these probabilities in a panel gravity model framework. Results show that macroeconomic variables asymmetrically impact stock market comovement across the return distribution. Financial liberalization significantly increases left tail comovement, whereas trade integration significantly increases comovement across all quantiles. Decreasing exchange rate volatility results in increasing lower tail comovement. The introduction of the euro increases comovement across the entire return distribution, thereby significantly reducing the benefits of portfolio diversification within the euro area.     

Attention allocation and international stock return comovement: Evidence from the Bitcoin market

We employ extreme Bitcoin returns as exogenous shock events to investigate the impact of investor attention allocation on worldwide stock return comovement. We find that (1) these shock events decrease worldwide stock return comovement, (2) there is an asymmetric effect in which a crash shock event has a greater impact on return comovement than a jump shock event, and (3) the impact of these shock events on equity comovement is more pronounced in emerging markets. Our results suggest that identifying extreme Bitcoin returns will benefit portfolio construction. Our results may be of considerable interest to investors, as well as to academics interested in portfolio diversification, asset comovement, and cryptocurrencies.     

An inverted U‐shaped crude oil price return‐implied volatility relationship

We examined the return–volatility relationship for USO ETF oil price return and CBOE Crude Oil ETF Volatility Index, OVX. The data for the USO and OVX covers the period covering May 11, 2007 to February 28, 2013. Our OLS regression results suggest evidence of regular feedback and leverage effects. When we employ linear quantile regression techniques, we find evidence of regular and inverse feedback effects. The inverse feedback effects being noticeable in the upper quantile region of the oil return distribution. There is also support for a regular leverage effect in USO prices. We also examined the return–volatility relationship using quantile regression copula methods for measuring the degree of asymmetry in the relationships between the oil price return and implied volatility. The results of the analysis indicate, first, that there exists a negative relationship between contemporaneous oil VIX and USO ETF oil returns. Second, that the relationship between oil returns and implied volatilities depends on the quartile at which the relationship is being investigated. Third, there exists an inverted U-shaped dependency relationship between returns and implied volatilities across quantiles. Fourth, though an inverted U-shape exists, the shape is different from those observed in stock markets.     

Price informativeness and stock return synchronicity: Evidence from the pricing of seasoned equity offerings

We investigate what stock return synchronicity reflects in terms of price informativeness by examining its effect on the pricing of seasoned equity offerings (SEOs). Based on 5,087 SEOs from 1984 to 2007, we find a significantly negative relation between stock return synchronicity (estimated as the logit transformation of the R-squared statistic from a two-factor regression) and SEO discounts (the percentage differences between pre-offer day closing prices and offer prices). The negative relation is strongest when there is no analyst coverage, and it declines as analyst coverage increases. This shows that stock price is more informative when stock return synchronicity is higher and also that information asymmetry can be mitigated by analyst coverage. We further decompose stock return synchronicity into the market comovement and industry comovement components and find that both components are equally important in affecting SEO discounts.     

Massively Confused Investors Making Conspicuously Ignorant Choices (MCI–MCIC)

This paper examines the comovement of stocks with similar ticker symbols. For one such pair of firms, there is a significant correlation between returns, volume, and volatility at short frequencies. Deviations from "fundamental value" tend to be reversed within several days, although there is some evidence that the return comovement persists for longer horizons. Arbitrageurs appear to be limited in their ability to eliminate these deviations from fundamentals. This anomaly allows the observation of noise traders and their effect on stock prices independent of changes in information and expectations.     

The comovement of option listed stocks

This study examines the changes in return comovement around the listing and delisting of stock option contracts. We show that newly option listed stocks experience an increase in comovement with a portfolio of option listed stocks and a decrease in comovement with the portfolio of non-optioned stocks. Similarly, stocks that undergo option delisting exhibit a decrease in comovement with option listed stocks and an increase in comovement with non-optioned stocks. We verify the reliability of our findings in several ways. A matched sample analysis suggests that our results are not driven by factors other than option listing and we find similar results using a calendar-time approach. Further analysis reveals that commonalities in option trading may induce the comovement in the option listed stocks. Overall, our evidence is consistent with the predictions of the category or habitat view of comovement.     

Timescale-dependent stock market comovement: BRICs vs. developed markets

This paper examines the differences in the asset return comovement of the BRIC countries (Brazil, Russia, India and China), the other developed economies in their regions (Canada, Hong Kong and Australia) and the major industrialized economies (the U.K., Germany and Japan) with respect to the U.S. for different return periods. The novelty of the paper is that the stock return indices are decomposed to several timescales using wavelet analysis and that the results are further used as inputs for the dynamic conditional correlation (DCC) framework, which is used as a measure of comovement. The results propose that the level of stock market comovement depends on regional aspects, the level of development and especially on the timescale of returns. These factors should be carefully considered in designing internationally diversified portfolios. The BRICs provide some portfolio diversification benefits, but it is not justifiable to treat all BRICs as a homogeneous group of emerging economies in terms of stock market comovement.     

Connected Stocks

We connect stocks through their common active mutual fund owners. We show that the degree of shared ownership forecasts cross‐sectional variation in return correlation, controlling for exposure to systematic return factors, style and sector similarity, and many other pair characteristics. We argue that shared ownership causes this excess comovement based on evidence from a natural experiment—the 2003 mutual fund trading scandal. These results motivate a novel cross‐stock‐reversal trading strategy exploiting information contained in ownership connections. We show that long‐short hedge fund index returns covary negatively with this strategy, suggesting these funds may exacerbate this excess comovement.     

Comovement,information production,and the business cycle

Recent theoretical research suggests that information production is a positive externality of aggregate economic activity (Veldkamp, 2005). Both the quantity and quality of information increase during periods of economic expansion and decrease during periods of contraction. Based on this insight, we hypothesize and confirm that time-varying information production drives the comovement patterns observed in stock returns. We examine stock return comovement in 36 countries from 1980 to 2007 and show that, consistent with the theory, comovement patterns are countercyclical; that is, when information production is high (low), comovement is low (high). We also find that the relation between comovement and the business cycle is stronger in countries that experience large intertemporal swings in information production. Finally, we show that the relation between business cycle and comovement is stronger in poor countries, countries with less developed financial markets, and countries with weaker accounting and transparency standards. These results suggest that financial development and transparency are conducive to a steady flow of financial information over the business cycle.     

The annual report tone and return Comovement—Evidence from China's stock market

Our paper uses A-share firms listed on Shanghai Stock Exchange (SSE) and Shenzhen Stock Exchange (SZSE) to explore the role of the textual tone of Chinese listed companies' annual reports on Chinese equities' return comovement. Our paper finds that the tone embedded in A-share companies' annual reports significantly increases Chinese stocks' return comovement as the tone exacerbates information asymmetry and reduces the quality of information. In addition, the annual report tone has a prominent effect on Chinese stocks' return comovement for stocks with low institutional ownership, private ownership stocks, and stocks with low market shares. Further investigation shows that the impact of the tone of the annual report on Chinese stocks' return comovement is strong during economic expansions, and when investor sentiment is high. An additional examination on hidden information in the textual tone suggests that published financial data do not explain a substantial part of the textual tone that is associated with the increase in the comovement, suggesting that private information should enhance informational opaqueness in the stock market.     

Does Voluntary Disclosure Improve Stock Price Informativeness?

According to theory, comovement in stock prices reflects comovement in the fundamental factors underlying the values of stocks. Recent theory contends that stock price comovement can be driven by information markets or the informational opacity of the firm. To the extent that voluntary disclosure reduces information acquisition cost and enhances firm transparency, we predict that enhanced voluntary disclosure reduces stock price comovement. We provide evidence in support of this prediction using analyst evaluation of firm disclosure policy. Overall, our evidence supports the effectiveness of firm disclosure policy in increasing the amount of firm‐specific information contained in stock returns.     

Time‐Varying Risk–Return Trade‐off in the Stock Market

We uncover a strong comovement of the stock market risk–return trade‐off with the consumption–wealth ratio (CAY). The finding reflects time‐varying investment opportunities rather than countercyclical aggregate relative risk aversion. Specifically, the partial risk–return trade‐off is positive and constant when we control for CAY as a proxy for investment opportunities. Moreover, conditional market variance scaled by CAY is negatively priced in the cross‐section of stock returns. Our results are consistent with a limited stock market participation model, in which shareholders require an illiquidity premium that increases with CAY, in addition to the risk premium that is proportional to conditional market variance.     

Structural holes and hedge fund return comovement: evidence from network-connected stock hedge funds in China

Using data from a new hedge fund database, we examine the impact of social networks on the return comovement of stock hedge funds in China. We use structural holes in the college alumni networks of managers to measure the managers’ social network positions. We perform an empirical analysis on a sample of 3,012 hedge fund products in China from 2010 to 2017. We find that greater structural holes are associated with higher return comovement. The positive impact of the structural holes on return comovement is not affected by market cycles, a manager's major in college, or his or her abilities.     

Correlation and return dispersion dynamics in Chinese markets

This paper studies the relation between firm-level return dispersions and correlations among Chinese stocks during periods of unusually large upward and downward swings. We analyze individual stock returns across 18 sectors and test if return dispersions and stock correlations show asymmetric patterns for extreme up and down markets. Evidence from studies on U.S. stocks suggests that equity return correlations tend to be much greater on the downside than on the upside and that the degree of comovement gets even stronger during extreme market states. However, in the case of Chinese stock market, we find that higher downside correlations apply to only stocks within the Financial sector. With the exception of Financial stocks, we find that stock correlations are significantly higher during up markets, rather than down markets. Regarding firm-level return dispersions, our findings are consistent with rational asset pricing model predictions. We find that equity return dispersions are significantly higher during periods of large price changes.     

Commonality in the time-variation of stock–stock and stock–bond return comovements

We jointly investigate time-varying comovements between stock returns across countries and between long-term government bond and stock returns within countries. Our focus is on how daily return comovements vary with stock uncertainty, as measured by the implied volatility (IV) from equity index options. Cross-country stock return comovements tend to be stronger (weaker) following high (low) IV days and on days with large (small) changes in IV. Stock–bond return comovements tend to be substantially positive (negative) following low (high) IV days and on days with small (large) changes in IV. A regime-switching analysis also indicates a striking temporal commonality in the stock–stock and stock–bond comovement variations. Our findings bear on understanding the influence of time-varying uncertainty on price formation and the diversification benefits of stock–bond and cross-country stock holdings.     

Shareholder Coordination,Information Diffusion and Stock Returns

We show that the quality of information‐sharing networks linking firms’ institutional investors has stock return predictability implications. We find that firms with high shareholder coordination experience less local comovement and less post‐earnings announcement drift, consistent with the notion that information‐sharing networks facilitate information diffusion and improve stock price efficiency. In support of the view that coordination acts as an information diffusion channel, we document that the stock return performance of firms with high shareholder coordination leads that of firms with low shareholder coordination.     

Sell‐Side Analyst Research and Stock Comovement

We document that a stock's price around a recommendation or forecast covaries with prices of other stocks the issuing analyst covers. The effect of shared analyst coverage on stock price comovement extends beyond analyst activity days. A stock's daily returns covary with the returns of other stocks with which it shares analyst coverage. These links between stock price comovement and shared analyst coverage are consistent with the coverage‐specific information we find in earnings forecasts; analysts who cover both stocks in a pair expect future earnings of the stocks to be more highly correlated than do analysts who cover only one stock from the pair. Collectively, our evidence indicates that analyst research produces coverage‐specific spillovers that raise price comovement among stocks that share analyst coverage. The strength of these spillovers is comparable to spillovers from broad industry and market information in analyst research.     

Stock and Bond Return Comovement as a Different Way to Assess Information Content: The Case of Debt Covenant Violation Disclosures

We propose a supplementary way to assess the information content of a financial statement disclosure based on the comovement of asset returns in different markets in response to information that has price implications for both. The influence of a signal that strongly influences at least two asset markets measures a dimension of information content less clearly reflected in single‐market responses. We apply our method to debt covenant violation (DCV) disclosures. These are the outcome of a debt renegotiation when the covenant promises in a debt agreement to manage the agency costs of debt are broken. We find that stock and bond return comovement is highest one day before DCV disclosure and differs depending on whether the debt covenant is waived or not waived. We find that stock and bond return comovement in the days following a DCV disclosure decreases more for non‐waiver disclosures than for waiver disclosures. This supports the theory that a non‐waiver outcome shifts control rights and bargaining power to the creditors. Consistent with this theory, single‐market tests show that bonds with a non‐waiver disclosure versus a waiver disclosure earn positive excess returns following a DCV disclosure whereas the reverse is true for stocks.