A comprehensive long-term analysis of S&P 500 index additions and deletions

We investigate the long-term effects of S&P 500 index additions and deletions on a sample of stocks from 1962 to 2003 and find a significant long-term price increase for both added and deleted stocks, with deleted stocks outperforming added stocks. The long-term price increase for added stocks can be attributed to increases in institutional ownership, liquidity, and analyst coverage, and a decrease in the shadow cost in the long-term. However, while deletion has no significant effect on analyst coverage and shadow cost, we find a rebound in the institutional ownership and liquidity of deleted stocks. The difference in the long-term price increase of added and deleted stocks can be explained by analyst coverage and operating performance.     

Free Float And Market Liquidity: A Study Of Hong Kong Government Intervention

The August 1998 Hong Kong government intervention in the stock market offers a natural experiment for studying the relation between a free float and market liquidity, where a free float is the portion of listed share capital that is freely traded on the market. Our findings show that, relative to a group of control stocks, there was an increase in the price effects of trades for the 33 Hang Seng Index component stocks that were bought by the government. On the other hand, there was no clear cross‐sectional relation between the change in the price effect and the magnitude of government holdings or the decrease in the free float.     

Understanding short-term price pressure from index reconstitutions: Evidence from the CSI 300

Motivated by the mixed results of the few prior studies, we focus on the short-term price performance of stocks added to or deleted from the CSI 300 Index. Consistent with the price pressure hypothesis, we evidence a temporary change in the prices of respective added and deleted stocks, followed by subsequent price reversions. To reconcile past studies, we also test several explanatory factors as potential sources of short-term price pressure. Results show that changes in investor trading behaviour, investor awareness, firm risk, and liquidity explain the short-term price pressure of added and deleted stocks, while changes in institutional trading, realised volatility, and liquidity explain the differences in the impact of reconstitutions between added and deleted stocks.     

首次公开募股(IPO)市场表现及破发影响——基于港市中资股的经验证据

以在港上市中资股2013—2019年的数据为研究样本,首先,基于典型事件分析中资股在境外资本市场的整体表现;然后,采用多元回归模型实证检验破发、市场状况及投资者态度等因素对中资股市场表现的影响。研究结果表明：相较于恒生指数,港市中资股IPO上市后两年内的整体市场表现处于劣势;IPO破发不利于后期市场的表现,破发股的整体市场表现差于非破发股;投资者行为是市场表现的重要影响因素之一,投资者意见分歧会对中资股的市场表现产生正向影响;新股上市前的市场环境越好,中资股IPO上市后的市场表现会越好。     

The liquidity effects of revisions to the S&P 500 index: an empirical analysis

We study liquidity effects following S&P 500 index revisions. Using a recent sample of S&P 500 additions, we find a sustained increase in the liquidity of the added stocks. Further, the improvement in the liquidity of added stocks is due primarily to a decrease in the direct cost of transacting and a smaller decline in the asymmetric information component. Finally, the event period cumulative abnormal returns for additions are significantly associated with the decrease in the effective spread, particularly the decline in the direct cost of transacting. In contrast, the liquidity of deleted stocks declines over the three months following deletion.     

Regulation and stock market quality: The impact of MiFID II provision on research unbundling

This paper investigates the effects produced by the unbundling of analyst research costs required by MiFID II on market quality, as measured by stock liquidity and price efficiency. We find that the payment of an explicit price for research is associated with a reduction in analyst coverage in the EU. Unexpectedly, the reduction is stronger for large-cap stocks. For mid- and large-cap stocks analyst coverage in the EU is still greater than in the US. The reduction in analyst coverage observed in the EU is part of a downward trend that initiated prior to MiFID II and contributes to close the gap between the two regions. We also find no change in the bid-ask spread for small-, mid- and large-cap stocks, and a slight increase for micro-cap stocks. We observe no significant change in price efficiency. Taken together our findings seem to suggest that there was an overproduction of research in Europe with the previous regulatory regime. However, the growth of passive management and index funds may also explain the observed decrease in coverage.     

What’s in the news? The ambiguity of the information content of index reconstitutions in Germany

We analyze stock price behavior around reconstitutions of the German DAX index family from 1990 to 2013. The strong price run-up of added stocks in the 2 months preceding the announcement date remains robust until 2 months after the effective date (ED), and is fully reversed 5 months later. Conversely, stock prices of deleted firms are under pressure until 10 months after the ED. Unlike most previous studies, we find that outright entries and exits have temporary price effects, as do additions to and deletions from better-known indices; however, promotions and demotions related to lesser-known indices command permanent stock price responses. Rather surprisingly, deleted stocks consistently earn higher abnormal returns than added stocks in the 5-year post-event period. Specifically, the return differential levels out at 77.3%. We establish that this differential in permanent stock prices is attributable to differences in operating performance and media coverage. In practice, index reconstitutions do not appear to give unambiguous signals about the long-run investment appeal of affected firms. However, index fund managers not constrained by tracking error minimization would be better off holding deleted stocks for 5 years after the ED.     

Does international cross-listing improve the information environment

We investigate whether cross-listing in the U.S. affects the information environment for non-U.S. stocks. Our findings suggest cross-listing has an asymmetric impact on stock price informativeness around the world, as measured by firm-specific stock return variation. Cross-listing improves price informativeness for developed market firms. For firms in emerging markets, however, cross-listing decreases price informativeness. The added analyst coverage associated with cross-listing likely explains the findings in emerging markets, rather than changes in liquidity, ownership, or accounting quality. Our results indicate that the added analyst coverage fosters the production of marketwide information, rather than firm-specific information.     

双重上市股票的价格信息传递——基于内地香港双重上市股票的实证分析

本文选取2003年到2007年4月的内地、香港双重上市股票为样本，运用似不相关（suR）方法实证考察两个市场之间的价格信息传递情况。研究发现：个股日内收益受A股市场大盘影响比同一只股票在香港市场受恒生指数的影响要大；股票价格信息主要由内地流向香港；A股的目内收益显著影响了同一天香港的日内收益，而A股的日内收益对香港隔夜收益的影响相对较弱。     

The First Analyst Coverage of Neglected Stocks

We examine the first analyst coverage of 549 “neglected” stocks that publicly traded at least one year without research coverage. The stocks experience a +4.86% abnormal return at initiation announcement. Positive returns are driven by positive coverage and not the mere introduction of coverage. Initiations from investment banks elicit lower announcement returns if the bank had a prior business relationship with the covered firm. Research firms paid by the covered company to provide coverage elicit announcement returns that are not significantly different from other analysts. Announcement returns are also influenced by liquidity increases and factors consistent with downward-sloping demand curves.     

Overreaction in the Hong Kong stock market

Overreaction reported in the equity markets of the United States, Spain, and Brazil is also observed in the Hong Kong stock market. The “loser” portfolios of the 33 stocks in the Hang Seng Index (HSI), on average, outperform the “winner” portfolios by 9.9% 1 year after the formation periods. Besides its emphasis on the importance of the Hong Kong market in international investment, this paper is unique in some special features related to the overreaction study. Hong Kong has markets for index futures and stock futures. Only three stocks are used in the portfolios. All the stocks in the HSI have large market capitalization and liquidity and can be shorted with no up-tick rule. Unlike other studies in international stock markets, the “arbitrage” portfolio of buying the loser portfolio and shorting the winner portfolio can actually be formed with minimum cost and easy execution, which makes the overreaction phenomena in this study very powerful.     

Stock index adjustments and analysts’ forecast optimism: A quasi-natural experiment on the CSI 300 Index

As stock index adjustments comprise a basic system of capital market, their potential influence on analysts’ earnings forecasts is worthy of research. Based on a research sample of 23 adjustments to the CSI 300 Index from June 2007 to June 2018 and the backup stocks announced during the same period, this study examines the impact of additions to stock index on analysts’ forecast optimism using a staggered difference-in-differences model. The research results show that after stocks are added to the stock index, analysts’ earnings forecast optimism about these stocks increases significantly. Cross-sectional analysis indicates that this increase is more significant when the market is bullish, institutional ownership is low, the ratio of listed brokerage firms is low, star analyst coverage is low, firms show seasoned equity offering activity, the ratio of analysts from the top five brokerage firms ranked by commission income is high, and the analysts’ brokerage firms are shareholders. However, analyst-level tests find that analysts’ ability helps to reduce the impact of additions to stock index on earnings forecast optimism. Furthermore, additions to stock index significantly increase analyst coverage and forecast divergence. Economic consequences tests find additions to stock index significantly increases stock price synchronization, which is partly mediated by analysts’ earnings forecast optimism. This study enriches the literature on the impact of basic capital market systems and analyst behavior. The findings suggest that investors should rationally evaluate analysts’ earnings forecasts for stocks added to the stock index and obtain further information from various channels to improve asset allocation efficiency.     

Lead-lag relationships in an embryonic stock market: Exploring the role of institutional ownership and liquidity

This paper investigates the influence of institutional ownership and liquidity on stock return relationships for an embryonic and relatively illiquid stock market. Using daily, individual stock data for Trinidad and Tobago from 2001 to 2015 and a VAR modelling approach, we find for firms of all sizes and levels of analyst coverage that the returns of more institutionally favoured stocks lead those with less institutional ownership. Distinctively, greater institutional coverage is shown not to be associated with greater liquidity, though liquidity levels do condition the influence of institutional ownership. This indicates that institutional owners have information advantages relative to other stock owners.     

Leverage-based index revisions: The case of Dow Jones Islamic Market World Index

US firms added to the Dow Jones Islamic Market World Index, a leverage-based index, witness permanent positive price and liquidity effects, whereas excluded firms sustain negative price and liquidity effects but no decrease in the investor awareness. Included/excluded firms experience a significant drop/no change in the cost of equity. Among the deleted firms, those with an increase in debt level bear a more severe decrease in liquidity and institutional ownership, and an increased cost of equity than those firms without an increase in debt use. Conveying private information on changes in a firm's corporate strategy and operating environment, revisions by a leverage-based index are different from those by size-based indexes.     

INSTITUTIONAL TRADING AND SECURITY PRICES: THE CASE OF CHANGES IN THE COMPOSITION OF THE S&P 500 INDEX

This paper examines the common stock valuation and liquidity effects of firms being added to and deleted from the S&P 500 Index. Three potential pricing and trading volume hypotheses are discussed and tested—an Information Content Hypothesis (ICH), a Price Pressure Hypothesis (PPH), and a Liquidity Cost Hypothesis (LCH). The empirical findings indicate that firms being added to (deleted from) the S&P 500 Index over the 1977 to 1983 period experience positive (negative) abnormal common stock returns on the day following the addition. An analysis of common stock liquidity around additions to the Index reveals that while relative trading activity increases in the month of addition, it actually declines in subsequent months. The valuation and liquidity results are consistent to some degree with both the PPH and the LCH and are most likely due to index fund managers adjusting their holdings to reflect changes in the Index.     

Stock market liquidity and firm value

This paper investigates the relation between stock liquidity and firm performance. The study shows that firms with liquid stocks have better performance as measured by the firm market-to-book ratio. This result is robust to the inclusion of industry or firm fixed effects, a control for idiosyncratic risk, a control for endogenous liquidity using two-stage least squares, and the use of alternative measures of liquidity. To identify the causal effect of liquidity on firm performance, we study an exogenous shock to liquidity—the decimalization of stock trading—and show that the increase in liquidity around decimalization improves firm performance. The causes of liquidity's beneficial effect are investigated: Liquidity increases the information content of market prices and of performance-sensitive managerial compensation. Finally, momentum trading, analyst coverage, investor overreaction, and the effect of liquidity on discount rates or expected returns do not appear to drive the results.     

The impact of H-share derivatives on the underlying equity market

We conjecture that an introduction of the Hong Kong Hang Seng Chinese Enterprise Stock Index (H-share Index) futures induces additional speculating activities in the underlying equities, leading to an increase in volatility and volume of the underlying stocks. Whereas, a subsequent introduction of H-share index options increases the level of informed trading and opens up opportunities for speculative and arbitrage activities using futures directly against options. These futures and options trading activities are much cheaper and more efficient than using the underlying stocks, leading to a significant decline in spot market volatility and volume. Our results are consistent with these arguments. We also find that derivative trading does not change the liquidity of H-share constituent stocks. Further tests based on the difference-in-difference approach confirm that the above findings are robust.

Relative informational efficiency of cash,futures, and options markets: The case of an emerging market

We study the lead–lag relationships among the spot, futures, and options markets on Hong Kong’s Hang Seng Index (HSI). The young options market experiences thin trading, and the option returns lag the cash index returns. The more mature futures market experiences active trading. Yet its lead over the cash index appears to be less than the counterparts in other countries. A possible reason is the dominance of a few major stocks in the index; and these stocks have symmetric lead–lag relations with the futures. Furthermore, the informativeness of the non-lasting futures and options quotations seems to depend on the market maturity.     

The liquidity effects associated with addition of a stock to the S&P 500 index: evidence from bid/ask spreads

This study examines changes in stock liquidity, as measured by the bid/ask spread, when a stock is added to the S&P 500 Index. The paper presents evidence of a significant decrease in the bid/ask spread upon S&P 500 addition, however, this effect is limited to only those stocks that were not trading listed options. Further, the decrease in the bid/ask spread for nonoptioned stocks is accompanied by a significant and permanent increase in share price and trading volume. While optioned stocks experience a permanent increase in trading volume, they experience only a temporary increase in share price. The findings for optioned stocks support the hypothesis that the price and volume effects associated with S&P 500 addition derive from temporary price pressure. Findings pertaining to the nonoptioned stocks indicate that the price and volume effects associated with S&P addition reflect enhanced stock liquidity. The decrease in the bid/ask spread for nonoptioned stocks is attributed to informational efficiencies achieved via index arbitrage trading, and it is argued that this effect is mitigated for optioned stocks due to the pre-existence of arbitrage trading between the option and the underlying stock.     

The impact of salient political and economic news on the trading activity

This paper investigates the impact of salient political and economic news on the intraday trading activity, namely, the stock return volatility, the stock price volatility, the number of shares traded, and the trading frequency. Using transactions data on 33 constituent stocks of the Hang Seng Index in the Stock Exchange of Hong Kong (SEHK), we find that political news has a distinct impact on market activity when compared with economic news. We argue that the observed phenomenon is related to the precision of signals associated with these two types of news and investors' perceptual biases.