Dispersion trading: Empirical evidence from U.S. options markets

This paper develops empirical evidence on the viability of a form of volatility trading known as “dispersion trading.” The results shed light on the efficiency with which U.S. options markets price volatility.Using end-of-day implied volatilities extracted from equity option prices for the stocks that comprise the S&P 500, the implied volatility of the S&P 500 is computed using a modification of the Markowitz variance equation. This Markowitz-implied volatility is then compared to the implied volatility of the S&P 500 extracted directly from index options on the S&P 500. These contemporaneous measures of implied volatility are then examined for exploitable discrepancies both with and without transaction costs. The study covers the period October 31, 2005 through November 1, 2007.It is shown that, from a trader's perspective, index option implied volatility tended to be more often “rich” and component volatilities tended to be more often “cheap.” Nevertheless, there were times when the opposite was true; suggesting that potential dispersion trades can run in either direction.     

The S&P500 index effect reconsidered: Evidence from overnight and intraday stock price performance and volume

This study focuses on S&P500 inclusions and deletions, examining the impact of potential overnight price adjustment after the announcement of an S&P500 index change. We find evidence of a significant overnight price change that diminishes the returns available to speculators although there are still profits available from the first day after announcement until a few days after the actual event. More importantly, observing the tick-by-tick stock price performance and volume effects on the key days during the event window for the first time, we find evidence of consistent trading patterns during trading hours. A separate analysis of NASDAQ and NYSE listed stocks allows for a detailed examination of the price and volume effect at an intra-day level. We find that index funds appear to cluster their rebalancing activities near to and after the close on the event date, suggesting that they are more concerned with tracking error than profit.     

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.     

Information costs and liquidity effects from changes in the FTSE 100 list

Abstract

In this paper we examine the stock price effect of changes in the composition of the FTSE 100 over the time period of 1984–2001. Like the S&P 500 listing studies, we find that the price and trading volume of newly listed firms increases. The evidence is consistent with the information cost/liquidity explanation. This is because investors hold stocks with more available information, implying that they have lower trading costs. This explains the increase in the stock price and trading volume of newly listed stocks to the FTSE 100 List. We find the reverse effect for the deletions from the FTSE 100.     

Do ADRs enhance portfolio performance for a domestic portfolio? Evidence from the 1990s

American depository receipts (ADRs) represent an increasingly popular and convenient mechanism for international investing. We analyze ADRs traded throughout the 1990s and find that these securities offer a diversification and portfolio performance benefit when combined with a domestic portfolio (proxied by the S&P 500). While we find that emerging market ADRs are effective instruments for reducing portfolio risk, they do not improve portfolio performance as measured by the Sharpe ratio. Developed market ADRs do improve portfolio performance as measured by the Sharpe ratio. The asset allocation which maximizes the Sharpe ratio is 84 percent domestic stocks, 16 percent developed ADRs, and 0 percent emerging ADRs. Further, due to problems in defining an appropriate market index for ADRs, the Sharpe ratio is viewed to be the preferred performance measure. Other measures such as Jensen’s alpha and the Treynor measure are susceptible to being “gamed” to distort portfolio performance.     

S&P 500 trading strategies and stock betas

This paper shows that S&P 500 stock betas are overstatedand the non-S&P 500 stock betas are understated becauseof liquidity price effects caused by the S&P 500 tradingstrategies. The daily and weekly betas of stocks added to theS&P 500 index during 1985-1989 increase, on average, by0.211 and 0.130. The difference between monthly betas of otherwisesimilar S&P 500 and non-S&P 500 stocks also equals 0.125during this period. Some of these increases can be explainedby the reduced nonsynchroneity of S&P 500 stock prices,but the remaining increases are explained by the price pressureor excess volatility caused by the S&P 500 trading strategies.I estimate that the price pressures account for 8.5 percentof the total variance of daily returns of a value-weighted portfolioof NYSE/AMEX stocks. The negative own autocorrelations in S&P500 index returns and the negative cross autocorrelations betweenS&P 500 stock returns provide further evidence consistentwith the price pressure hypothesis.     

What Drives the S&P 500 Inclusion Effect? An Analytical Survey

We present an analytical survey of the explanations—price pressure, downward-sloping demand curves, improved liquidity, improved operating performance, and increased investor awareness—for the increase in stock value associated with inclusion in the S&P 500 Index. We find that increased investor awareness is the primary factor behind the cross-section of abnormal announcement returns. We also find some evidence of temporary price pressure around the inclusion date. We find no evidence that long-run downward-sloping demand curves for stocks, anticipated improvements in operating performance, or increased liquidity are related to the cross-section of announcement or inclusion returns.     

S&P 500 index addition,liquidity management and Tobin's Q

This study examines the revision in cash holdings and the market valuation of investment opportunities of 475 firms added to the Standard & Poor's 500 (S&P 500) stock market index from 1980 to 2010. We find that newly indexed firms have evolved to significantly lower cash balances, which we partially explain by the decreasing growth opportunities following index inclusion. Consistent with index inclusion loosening financial constraints, we document a larger decrease in cash for index inclusions in sectors with high financial dependence. We sort S&P 500 inclusions by corporate governance quality but do not find any empirical support that changes in cash and Tobin's Q are related to management entrenchment.     

Strategic trading by index funds and liquidity provision around S&P 500 index additions

We examine the trades of index funds and other institutions around S&P 500 index additions. We find index funds begin rebalancing their portfolios with the announcement of composition changes and do not fully establish their positions until weeks after the effective date. Trading away from the effective date is more prevalent for stocks with lower levels of liquidity and among large index funds, which is consistent with index funds accepting higher tracking error in order to reduce the price impact of their trades. Small and mid-cap funds provide liquidity to index funds around additions, and added stocks with a greater proportion of these natural liquidity providers experience lower inclusion returns.     

PRICE AND VOLUME EFFECTS ASSOCIATED WITH THE CREATION OF STANDARD & POOR'S MIDCAP INDEX

In this paper we explore price and volume effects associated with the 1991 creation of Standard & Poor's MidCap 400 index. Prior work on changes in the composition of existing indices finds a significant price response to the announcement. Various authors link the effect to price pressure, information, an outwardly shifting demand curve for securities, and the increased attention that comes with inclusion in an index. Using event study methodology, we find significant price and volume effects during the two weeks leading up to the Standard & Poor's announcement, but no significant effect in the two-day interval around the event. Apparently, information leakage and/or anticipation preceded the creation of the index. The price run-up is permanent since the positive abnormal returns leading up through the announcement are not associated with significantly negative abnormal returns after the announcement. In addition, MidCap stocks significantly outperform the market during the fifty-two weeks following the announcement. Using cross-sectional regressions, we show that these prior-period abnormal returns are positively related to abnormal volume and institutional holdings. We also find that firms trading over-the-counter had larger price run-ups than NYSE or AMEX firms.     

Stock price and systematic risk effects of discontinuation of corporate R&D programs

We extend the evidence on whether investors impound efficiently into stock prices new disclosures about corporate R&D programs. We find that firms that disclose the discontinuation of some of their R&D programs experience a significant negative announcement-period stock price response which is worse for growth stocks, for small-size firms, and for firms with low operating cash flow. We find no evidence that R&D discontinuing firms experience an event-induced change in their systematic risk. We find evidence of a one-year-long price reversal; however, it is not robust to controlling for possible risk dimensions for firms with R&D capital that the three-factor model does not capture. Evidently, investors' initial response at disclosures of discontinuation of corporate R&D programs is efficient.     

What's in the News? Information Content of S&P 500 Additions

I investigate the information content of S&P 500 index changes by examining the price and volume reaction of the industry and size matched firms. Using a sample of S&P 500 additions between 1976–2001, I find a significantly positive price reaction, but no volume reaction, for the matching firms. In addition, the matching-firm price reaction is negatively related to the added firm's weight in its industry. These findings suggest that the index addition conveys favorable information about the added firm and its industry.     

资本市场国际影响力提升效应研究——来自A股纳入明晟(MSCI)新兴市场指数的证据

2018年5月15日,首批纳入明晟(MSCI)新兴市场指数的A股股票名单正式公布。我们发现,被纳入MSCI的股票(标的股票)在公告日前后有显著为正的累计超额收益。相较于主要特征相似的匹配股票,标的股票纳入MSCI后的分析师评级有显著提升。进一步研究表明,在公告日前后融资(融券)交易量显著上升(下降),而换手率没有明显变化,并且净融资交易与公告效应显著正相关。本文的发现表明,A股纳入MSCI这一事件具有明显的信息含量,传递了有关企业前景的正面信息,并促使本地市场聪明投资者进行更活跃的交易,这对促进价格发现、促成价值投资具有一定的推动作用。     

Trading around macroeconomic announcements: Are all traders created equal?

This paper examines the effects of macroeconomic announcements on equity index markets using high frequency transactions data for the regular and E-mini S&P 500 index futures contracts. For ten types of announcements that significantly affect prices, we analyze the price adjustment process and the trading patterns of exchange locals and off-exchange customers around the announcements. We find a large increase in trading activity immediately after the announcement. The results also show that during this initial surge in trading activity, locals are able to time their trades better than off-exchange traders even when locals do not have the advantage of access to the order flow. The trading strategy followed by exchange locals in the first 20 seconds after the announcement tends to be profitable, while off-exchange traders tend to make losing trades over the same time period. These results lend evidence that local traders tend to react to the macroeconomic information faster than off-exchange traders.     

Institutional investor’ proportions and inactive trading

We focus on a typical market anomaly-inactive trading: trading volume shrinks while stock price abnormally jumps. We calibrate a theoretical model with variance ambiguity heterogeneous among investors and illustrate that ambiguity averse investors' proportions enhance trading volume shrinkage and abnormal price jumps. We provide a cross-section analysis of stocks' inactive trading by introducing institutional investors' proportions to measure investor structures' differences among stocks. We also empirically measure relative inactive trading for constituent stocks in S&P 500 from 2014 to 2019 and demonstrate that institutional investors' proportion is negatively related to inactive trading. Finally, we demonstrate that higher proportions of institutional investors lead to less inactive trading anomalies.     

Do Demand Curves for Small Stocks Slope Down?

Stocks added to the S&P 500 generally experience positive abnormal returns following the announcement. Several competing explanations exist for this reaction, but small sample sizes and other issues make it difficult to distinguish among them. We examine this subject using the small‐cap Russell 2000 index, which has several advantages over the S&P 500 in this context. Our primary finding is that stocks added to or deleted from the Russell 2000 experience significant changes in stock price and trading volume, but the effect is transitory. The results support the price pressure hypothesis.     

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.     

Barron’s most respected companies

In this study, we investigate the performance of firms selected to Barron’s Most Respected Companies against the S&P 500 and a matched sample over a short‐term, long‐term and operational basis. The most respected companies exhibit a statistically significant announcement effect associated with their selection and outperform the S&P 500 over longer‐holding periods. The overall sample and those firms identified as top picks outperform a matched sample of firms. In addition, as measured by changes in the return on assets, the post‐selection operational performance of the most respected firms was better than that of the matched firms.     

Firm Opacity Lies in the Eye of the Beholder

We classify and test empirical measures of firm opacity and document theoretical and empirical inconsistencies across these proxies by testing the relative opacity of banks versus non‐banks. We evaluate the effectiveness of these proxies by observing the effect of two cleanly identified shocks to firm‐specific information: credit rating initiation and inclusion in the S&P 500 index. Using a difference‐in‐difference approach, we compare firms that are newly rated and firms that are included in the S&P 500 index with a propensity matched sample of “unchanged” firms. We find that only the number of analysts and Amihud's illiquidity ratio provide consistent patterns across different estimation specifications and different econometric settings. These two proxies show that banks are more opaque than non‐banks. Based on our tests, we recommend that these proxies be used as the primary measures of firm opacity.     

Overreaction of country ETFs to US market returns: Intraday vs. daily horizons and the role of synchronized trading

In this paper we study the intraday price formation process of country Exchange Traded Funds (ETFs). We identify specific parts of the US trading day during which Net Asset Values (NAVs), currency rates, premiums and discounts, and the S&P 500 index have special effects on ETF prices, and characterize a special intraday and overnight updating structure between these variables and country ETF prices. Our findings suggest a structural difference between synchronized and non-synchronized trading hours. While during synchronized trading hours ETF prices are mostly driven by their NAV returns, during non-synchronized trading hours the S&P 500 index has a dominant effect. This effect also exceeds the one that the S&P 500 index has on the underlying foreign indices and suggests an overreaction to US market returns when foreign markets are closed.