Informed Trading in Stock and Option Markets

We investigate the contribution of option markets to price discovery, using a modification of Hasbrouck's (1995) "information share" approach. Based on five years of stock and options data for 60 firms, we estimate the option market's contribution to price discovery to be about 17% on average. Option market price discovery is related to trading volume and spreads in both markets, and stock volatility. Price discovery across option strike prices is related to leverage, trading volume, and spreads. Our results are consistent with theoretical arguments that informed investors trade in both stock and option markets, suggesting an important informational role for options.     

On the Distribution of CBOE Option Trade Prices Occurring Between Consecutive Stock Trades

This paper examines the volume distribution of option trade prices that occurs when the underlying stock price remains constant. The width of these option trade price bands provides direct evidence on the law of one price and the redundancy of options assumed in many option models. We find that index option bands are narrower than equity option bands. Furthermore, for both equity and index options, puts have narrower bandwidths than calls. In general, option price bandwidth is narrow and can be explained by the minimum price movement allowed by the Chicago Board Options Exchanges (CBOE). This supports the single price law and the redundancy assumption. The existence of bid/ask quotes on the option does not materially affect the above results although it does alter the frequency of multiple option trade prices for a given underlying stock price. We note that over 53% of option trading volume occurs without bid/ask quotes on the CBOE compared to less than 15% a decade ago. Our results suggest that the effective bid/ask spread on options is probably no larger than the minimum price movements allowed by the CBOE. Furthermore, the need for the liquidity services of market makers may be declining if the decline in quoting activity stems from cross trading (i.e. trades not involving market makers).     

Volume,volatility and information linkages in the stock and option markets

This paper examines the relationship between option trading activity and stock market volatility. Although the option market is uniquely suited for trading on volatility information, there is little analysis on how trading activity in this market is linked to stock price volatility. The bulk of the discussion tends to focus on whether trading activity in the stock market is informative about stock volatility. To analyze the information in option trading activity for stock market volatility, a sample of 15 stocks with the highest option trading volume is selected. For each stock, it is noted that the trading activities in the put and call option markets have significant explanatory power for stock market volatility. In addition, the results indicate that the call option trading activity has a stronger impact on stock volatility compared with that of the put options. Our results demonstrate that information and sentiment in the option market is useful for the estimation of stock market volatility. Also, the significance of the effects of option trading activity on stock price volatility is observed to be comparable to that of stock market trading activity. Furthermore, the persistence and asymmetric effects in the volatility of some stocks tend to disappear once option trading activity is taken into account.     

Informed Trading around Merger Announcements: An Empirical Test Using Transaction Volume and Open Interest in Options Market

This paper provides empirical evidence on the level of trading activity in the stock options market prior to the announcement of a merger or an acquisition. Our analysis shows that there is a significant increase in the trading activity of call and put options for companies involved in a takeover prior to the rumor of an acquisition or merger. This result is robust to both the volume of option contracts traded and the open interest. The increased trading suggests that there is a significant level of informed trading in the options market prior to the announcement of a corporate event. In addition, abnormal trading activity in the options market appears to lead abnormal trading volume in the equity market. This finding supports the hypothesis that the options market plays an important role in price discovery.     

Stock price decreases prior to executive stock option grants

This study examines abnormal stock price changes prior to executive stock option grants. Executives have the incentive and opportunity to manage the timing of their communications of inside information to the market during the period just prior to the date of their stock-option grant so as to reduce the exercise price of their options. Executives benefit from temporary stock price decreases before the grant date and by stock price increases after the grant date. Executive stock option grants create a unique opportunity for insiders to profit by manipulating the timing of information flowing to the market without engaging in insider trading. Using data on 783 stock-option grants to chief executive officers, we find a statistically significant abnormal decrease in stock prices during the 10-day period immediately preceding the grant date.     

Speculative dynamics and price behavior in the Shanghai Stock Exchange

This article examines the extent to which the trading behavior of heterogeneous investors manifests in stock price changes of asset portfolios which constitute the Shanghai Stock Exchange. There are three major findings that materialize. Firstly, reliable statistical evidence of a negative relation between the conditional first and second moments of the return distributions of stock prices lends support to the volatility feedback effect. Secondly, ‘feedback’, or momentum-type investors, are not present in this market as is often detected from the daily price changes of other industrialized markets. Finally, trade volume as a proxy for ‘information-driven’ trading suggests that such investors play a statistically significant role in stock price movements. Parameter estimates from this latter group of investors imply that a rise in stock prices from a high volume trading day is more likely than a rise resulting from a low volume trading day.     

Informed traders and their market preference: Empirical evidence from prices and volumes of options and stock

The causal structure of price and volume in options and stock markets is examined to investigate whether a preferred market for informed trading exists. The possible trade-off of leverage on one hand and liquidity and transactions costs on the other, and the effect of different market mechanisms, are discussed in this context.We test for cointegration and use the vector error correction (VEC) approach if we find it. Otherwise, causality tests are via the conventional vector autoregression (VAR). We find that volume leads price in both markets, but that option volume leads stock volume, and stock price leads option price. These results differ from previous studies. Potential explanations are discussed.     

Earnings Announcements,Stock Price Adjustment,and the Existence of Option Markets

This paper employs a new approach to study the effects of option trading on the behavior of underlying stock prices. Extant research compares distributional properties of the stock price at two points in time divided by an event in the option market that might affect price behavior. As an alternative, we examine the stock price adjustment to the release of quarterly earnings using samples of firms with and without listed options. We find the two samples exhibit different adjustment processes, with the nonoption firms requiring substantially more time to adjust.     

Institutional Investor Participation and Stock Market Anomalies

This paper investigates the impact of institutional trading volume on stock market anomalies. The paper proposes a measure that evaluates the percentage of total trading volume of a stock accounted for by institutional trades. The empirical analyses using a large sample of firms from 1980–2005 provide strong evidence that the strength of stock market anomalies such as price momentum, post‐earnings announcement drift, the value premium, and the investment anomaly is decreasing in institutional trading volume. Additionally, the effects of institutional trading volume are stronger than those of institutional ownership, the major measure of institutional investor participation in the finance literature. These findings suggest that institutional trading significantly improves stock price efficiency.     

The Informational Role of Stock and Option Volume

This article analyzes the intraday interdependence of orderflows and price movements for actively traded NYSE stocks andtheir Chicago Board Options Exchange (CBOE)-traded options.Stock net trade volume (buyer-initiated volume minus seller-initiatedvolume) has strong predictive ability for stock and option quoterevisions, but option net trade volume has no incremental predictiveability. This suggests that informed investors initiate tradesin the stock market but not in the option market. On the otherhand, both stock and option quote revisions have predictiveability for each other. Thus, while information in the stockmarket is contained in both quote revisions and trades, informationin the option market is contained only in quote revisions.     

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.     

An Empirical Examination of the Return Volatility-Volume Relation in Related Markets: The Case of Stock and Options

This paper empirically examines the impact of option trading on the relation between daily stock return volatility and stock trading volume. For a sample of firms for which options were newly listed on the CBOE from 1982 to 1985, the empirical evidence indicates that there is a structural shift in the relation after option trading is introduced. Also, the findings show that daily stock return volatility is significantly and positively correlated with contemporaneous option volume, but not one-day lagged option volume. These results suggest that contemporaneous option volume may be an important variable in modelling daily stock return volatility and heteroskedasticity.     

THE INFLUENCE OF ORGANIZED OPTIONS TRADING ON STOCK PRICE BEHAVIOR FOLLOWING LARGE ONE-DAY STOCK PRICE DECLINES

In this study I examine the effect of organized options trading on stock price behavior immediately following stock price declines of 10 percent or more. A matched-pair sample of National Market System option and nonoption firms are analyzed from June 1985 through December 1992. After controlling for the bid-ask bounce, firm size, share price, return standard deviation, and beta, I find that three-day cumulative abnormal returns for option firms are approximately 1.57 percent less than those for nonoption firms. Thus, options trading enhances stock market efficiency and/or liquidity. However, no profitable trading strategies are indicated.     

Volatility Information Trading in the Option Market

This paper investigates informed trading on stock volatility in the option market. We construct non-market maker net demand for volatility from the trading volume of individual equity options and find that this demand is informative about the future realized volatility of underlying stocks. We also find that the impact of volatility demand on option prices is positive. More importantly, the price impact increases by 40% as informational asymmetry about stock volatility intensifies in the days leading up to earnings announcements and diminishes to its normal level soon after the volatility uncertainty is resolved.     

Do option markets substitute for stock markets? Evidence from trading on anticipated tender offer announcements

Using a sample of cash tender offers occurring between 1993 and 2002, we find evidence that the options market has become the preferred venue for traders attempting to profit on anticipated announcements. Options offer advantages relative to stocks. Traders gain leverage by trading in options and multiple options contracts on an individual stock. The results of our study indicate that a substitution effect does exist. Abnormal volume in the option market replaces abnormal volume in the stock market prior to cash tender offer announcements, and this abnormal option volume precedes abnormal stock volume for targets with or without traded options.     

The Relationship Between Stock and Option Price Changes

This paper documents an important step in reconciling conflicting results by Manaster and Rendleman [16] and Stephan and Whaley [21] regarding price change relationships between options and their underlying stocks. Using recent advances in bi-directional causality testing and data sources available only fairly recently, statistical tests are conducted that mitigate the nonsynchroneity and bid-ask bias problems that may have affected the Manaster and Rendleman [16] study. Even with these adjustments, empirical results are consistent with Manaster and Rendleman [16], indicating that stock price changes adjust to lagged option price changes over two trading days. Moreover, results suggest that the causality is bi-directional.     

Empirical Tests of Boundary Conditions for Toronto Stock Exchange Options

Using option and stock transaction data for the period 1978–1979, three issues were investigated: first, the conformance of observed prices to various boundary conditions; second, the evolution of the market over time, as the volume of trading and the number of listed options increased; and third, to test the efficiency of the market. It was found that violations did occur. Using a trading rule based on the signal of observed violations, the results suggest that even after transaction costs the market was inefficient over the sample period.     

The Intraday Relation between NYSE and CBOE Prices

I extend the literature regarding price discovery across stock and option markets through an empirical model that allows information to flow through an error‐correction term and volatility. NYSE prices tend to lead CBOE prices by at least thirty minutes over the entire six‐year sample period. In addition, informed trading in the options market is revealed more strongly through persistence in volatility and the spillover of volatility to the stock market than it is through returns.     

The Cross-Sectional Relationship Between Trading Costs and Lead/Lag Effects in Stock & Option Markets

Prior empirical research has failed to settle the question of lead/lag effects between stock and option markets. This study investigates the relation between cross-sectional differences in trading costs and intraday lead/lag effects in stock and option markets. The data for the study comprise 19 firms sampled at five-minute intervals over a two-month period. Consistent with a trading cost hypothesis, results indicate overall stock market leading behavior. However, the lead appears to be related to option market trading costs. This study uses an error correction model framework to investigate the lead/lag effects. This approach provides information on both the long run equilibrating process as well as the short term interactions between stock and option markets. Information regarding the long run equilibrating process is important to the overall understanding of lead/lag effects and cannot be determined from time series models of differenced data. Specific criteria for assessing lead/lag effects in cointegrated series are also proposed. One advantage of these new criteria is their ability to identify leading behavior in the presence of feedback. All models are estimated with quote data and are constructed to eliminate overnight effects. Hence, the results are robust to previously identified distortions due to closing, overnight, and potential non-trading effects. However, caution should be employed in generalizing the results as the study covers a two-month trading period for a limited number of firms.     

Price discovery in the U.S. stock and stock options markets: A portfolio approach

Option prices vary with not only the underlying asset price, but also volatilities and higher moments. In this paper, we use a portfolio of options to seclude the value change of the portfolio from the impact of volatility and higher moments. We apply this portfolio approach to the price discovery analysis in the U.S. stock and stock options markets. We find that the price discovery on the directional movement of the stock price mainly occurs in the stock market, more so now than before as an increasing proportion of options market makers adopt automated quoting algorithms. Nevertheless, the options market becomes more informative during periods of significant options trading activities. The informativeness of the options quotes increases further when the options trading activity generates net sell or buy pressure on the underlying stock price, even more so when the pressure is consistent with deviations between the stock and the options market quotes. JEL Classification C52, G10, G13, G14