Interaction of investor trades and market volatility: Evidence from the Tokyo Stock Exchange

This paper examines the relation between market volatility and investor trades by identifying who supplies and demands market liquidity on the Tokyo Stock Exchange. Because the different trading patterns of various investor types such as individual investors, institutional investors, and foreign investors affect market liquidity differently, we find that market volatility fluctuates significantly depending on which investor types participate in trade. We show that market volatility increases by more than 50% from the average level when there are greater buy trades by momentum investors that demand liquidity and there are less sell trades by contrarian (or profit-taking) investors that supply liquidity. On the other hand, volatility dampens by more than 57% when there are greater sell trades by profit-taking investors, mostly by domestic investors, while there are less momentum buy trades.     

Does vega-neutral options trading contain information?

This study suggests a novel approach for decomposing net options demands into the options order imbalances with and without volatility risk. By analyzing a high-frequency index futures and options dataset, we examine the information content of (i) the direction-motivated order imbalance induced by a single option type, which is exposed to volatility risk, and (ii) that constructed by both calls and puts, which is vega-neutral. The aggregate options order imbalance does not convey information after controlling for futures market trading. However, the intraday options order imbalance by trading without volatility risk significantly predicts spot index returns, though its longer-horizon forecasting ability is relatively weak because of a possible cross-market hedging effect. The predictive abilities of informed foreigners’ trades and out-of-the-money options trading are prominent. Our empirical results suggest that the vega-neutral options trading conveys additional information distinct from the futures order imbalance.     

Distilling private information from plain-vanilla options to predict future underlying stock price volatility: Evidence from the H-shares of Chinese banks

Deviations from put-call parity may arise in response to private information that a select group of investors possess. From a practical perspective, if one possesses private information, using options to speculate or hedge amplifies potential gains given the leverage embedded in options with respect to price changes in the underlying asset. In light of this, and if we assume that the average investor does not possess private information, it is perhaps possible though to infer such information through implied variance spreads and use it to predict future volatility in the underlying asset. In this piece I examine the extent to which such information is economically informative in predicting the intraday return variability of H-shares issued by China's state and joint-stock banks, respectively. Generally speaking, I uncover the following; firstly, call-put implied variance spreads are mean-reverting across time. Secondly, at any given point in time, the magnitude of the deviation from put-call parity is informative in predicting rises in future spot price volatility. Thirdly, straddle/strangle trades predict, at times one week in advance, rises in future spot price volatility. These findings hold after controlling for market-wide implied volatility, the flow and shock in information disseminating to the market, and implicit transactions costs.     

Market ambiguity and individual investor information demand

We examine whether ambiguity in the market leads to an increase in information demand by individual investors. Drawing on the asset-pricing model proposed by Mele and Sangiorgi (2015), which incorporates market ambiguity, we measure individual information demand using daily Google searches and measure market ambiguity using a metric based on the market trades of institutional investors. We find that individual investors increase their information demand during periods of greater market ambiguity. We also provide evidence that information demand from individual investors spikes around earnings announcement days primarily when market uncertainty is driven by net-selling activity. Overall, these results suggest that the disagreement among institutional investors either represents uncertainty or contributes to the uncertainty related to a stock, leading to increased demand for information from individual investors.     

The impact of foreign equity flows on market volatility during politically tranquil and turbulent times: The Egyptian experience

Since the popular uprising of January 2011, a series of momentous events has rocked Egypt’s political order, jeopardising the country’s economic and financial stability. This study examines the role of foreign capital flows in the volatility of the Egyptian equity market, and whether this role has changed due to the recent domestic political unrest. These issues are empirically addressed in the context of GMM estimation. The results suggest that, unlike those of foreign individual investors, trades of foreign institutional investors contribute to market fluctuations, whether prior to or following the January 2011 uprising. Sell trades by foreign individual and institutional investors exert a significant influence on volatility. Further, when volume is split into its anticipated and unanticipated components, the results show that surprises in trading activity by either group tend to exacerbate volatility in periods of calm and turmoil. These findings are broadly insensitive to volatility measures and robust, even after controlling for a variety of relevant determinants of market volatility. The evidence documented in this study provides important implications for policy markers.     

Co-movements of index options and futures quotes

We report evidence that the co-movements of index options and index futures quotes differ sharply from perfect correlation in periods with option trades. In half-hour intervals with (without) option trades 25% (12%) of call option quote changes have either the opposite sign or are larger in magnitude than the corresponding index futures quote changes. We calibrate a stochastic volatility model that allows for trade and no-trade periods using real data and simulate the joint co-movements of index quotes and option quotes in this model. We show that for trade intervals the observed co-movements differ from the benchmark case established by our simulations approximately three times too often. We provide empirical evidence that market microstructure effects – specifically, stale quotes and aggressive quotes – explain the majority of the deviations from the benchmark. Our findings are relevant for techniques that use estimates of local co-movements as inputs to price or hedge options.     

Market Reform and Efficiency: The Case of KOSPI200 Options

The Korean government and exchange have identified a need to regulate excessive speculative trading and to protect domestic individual investors from foreign and professional traders. As such, they have proposed an options market reform that requires higher levels of margin accounts for options trading and that increases the basic options multipliers in the KOSPI200 options market. This study examines how this market reform affects the price disagreement and adjustment behaviors of the index options market. Our analyses indicate that the efficiency and information quality of out-of-the-money options trades have increased since the reform took effect.     

The information content of ETF options

We examine the information content of China's Shanghai Stock Exchange (SSE) 50 ETF options introduced in 2015. Trading volume and implied volatilities of calls versus puts differ markedly: trading volume is consistently higher for calls, and implied volatility is higher for puts. Put-call volume and implied volatility ratios are not good predictors of future SSE 50 returns. Implied volatility follows a right-skewed smirk across strike prices, indicating a tendency among option traders to turn bullish and expect the stock market to recover from the June 2015 market crash. The options market dominates the price discovery process, with an average information leadership share of 67%. Our price discovery results persist during the COVID outbreak.     

The options market response to accounting earnings announcements

We examine the reaction of the equity options market to accounting earnings announcements over the period 1996–2008 using changes in implied volatility to measure the options market response to earnings news. We find that positive earnings surprises and positive profit announcements produce a larger uncertainty resolution than negative earnings surprises and loss announcements. We demonstrate an inverse relation between the change in implied volatility and earnings news in a three-day window immediately after an earnings announcement. We refer to the magnitude of this relation as the ‘options market earnings response coefficient’. This ‘options market earnings response coefficient’ is stronger for both bad news announcements and positive profit announcements. We do not find any significant relation between changes in implied volatility and earnings news in the pre- or post-announcement periods. We conclude that the options market efficiently absorbs earnings information.     

Does information drive trading in option strategies?

We study trading in option strategies in the FTSE-100 index market. Trades in option strategies represent around 37% of the total number of trades and over 75% of the total trading volume in our sample. We find some evidence that order flow in volatility–sensitive option strategies contains information about future realized volatility. We do not find evidence that order flow in directionally–sensitive option strategies contains information about future returns. Overall, our evidence suggests that option strategies are used both by traders who possess non-public information about future volatility and by uninformed speculators who appear to follow unprofitable trend chasing strategies.     

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.     

Informed arbitrage with speculative noise trading

We consider speculative noise trading when some naïve speculators trade on noise as if it were information [Black, F., 1986. Noise. Journal of Finance 41, 529–543]. We examine the optimal trading strategy of an informed investor who faces such naïve speculators in the market. We find that the informed investor trades aggressively on her information and takes large, opposite positions against the naïve speculators. The trading volume is thereby drastically magnified. While such speculative noise trading enhances liquidity, it makes prices less efficient. The overall dynamic patterns that emerge from our model are most consistent with the evidence for interday variations in volume, volatility, and transaction costs.     

Intraday volume and volatility relations with and without public news

This paper reexamines the dynamic relation between intraday trading volume and return volatility of large and small NYSE stocks in two partitioned samples, with and without identifiable public news. We argue that the sequential information arrival hypothesis (SIAH) can be tested only in periods containing public news. After partitioning the sample into periods with and without public news, we find bi-directional Granger-causality between volume and volatility in the presence of public information as hypothesized by the SIAH. Our analysis further suggests that return volatility is higher in the periods with public news, while trading volume is significantly higher in the no-news period; perhaps owing to the importance of private information for trading stocks. Using the sample without public news, we find evidence that volume Granger-causes volatility without feedback. These results are broadly consistent with behavioral models like the overconfidence and biased self-attribution model of [Daniel, K., Hirshleifer, D., Subrahmanyam, A., 1998. Investor psychology and security market under- and over-reactions. Journal of Finance 53, 1839–1885]. It appears that overconfident investors overrate the precision of their private news signals and therefore trade too aggressively in the absence of public news; when public news arrives, investors’ biased self-attribution triggers excessive return volatility.     

Intraday trading volume and international spillover effects

The objective of this paper is to explore whether lagged trading activity in one market contributes to the return and volatility process in other markets, using 5-min concurrent data from German and British equity market. Our results lend support to our initial premise that if international investors have access to the same information set as domestic traders, then after observing foreign trading activity, market makers adjust prices to reflect their expectation of the security value, conditional upon all available information, including prior trades. Our findings clearly indicate that intraday trading volume contains predictive power for cross-border return and volatility processes. Moreover, these volume effects are found to be asymmetric in the sense that the impact of positive volume changes upon foreign stock market volatility is greater than is the impact of negative changes.     

交易所大宗交易流动性折价研究——来自沪深交易所的经验证据

随着证券市场规模的扩大及机构投资者规模的壮大，机构投资者对市场流动性的需求日益剧增，大宗交易制度是满足投资者流动性需求的制度性创新。由于大宗交易的数量较大，其交易价格有别于正常交易规模的价格。本文利用沪深交易所的大宗交易数据实证探讨大宗交易价格及其影响因素。研究结果表明，大部分大宗交易价格低于当日收盘价格，呈现流动性折价现象，折价率达到1．27％：研究还发现，折价水平还受交易数量、正常交易时间段股票流动性水平、市场流动性水平及股价波幅等因素影响。     

Does informed trading occur in the options market? Some revealing clues

This paper analyses the relationship between proxy variables for informed trading in the options market and a set of exogenous news variables. The aim was to test directly for the presence or absence of informed trading in the options market and for the possible impact of this trading on underlying asset prices. Our findings reveal that potential informed trading in options markets is channelled basically through out‐of‐the‐money options, except for volatility trading which mainly involves at‐the‐money options because of their liquidity. In both cases, we have found evidence in favour of investors’ strategic fragmentation of transactions into intermediate size trades (stealth trading). Finally, it is shown that lack of consensus among agents also generates increased trading, particularly in out‐of‐the‐money and at‐the‐money options.     

Public re-release of going-concern opinions and market reaction

This paper examines the market reaction to the public announcement of going-concern (GC) opinions through the news media. In the early 2000s, NASDAQ and AMEX required firms listed on their exchanges to publicly announce previously disclosed information, such as the issuance of a GC opinion, through a press release or the news media. We examine the stock market reaction to the re-release of GC opinions. We find significant abnormal stock return volatility and trading volume at the re-release of this information. Further, based on an analysis of intraday transactions, we find higher abnormal trading activity in small trades around the re-release of the GC opinion, but largely no changes in large trades during the same period. In this respect, the investors that initiate the small trades act as if they are surprised by the information contained in the press release of GC opinions. Such an action, in turn, can be viewed as evidence of a delayed response to the information in GC opinions by a section of investors.     

Are They Hedgers or Speculators? Evidence from South Korea's Political Elections

This study uses a simultaneous equation model based on a three-stage least squares estimation to offer new empirical evidence that investors are hedgers or speculators during South Korea's elections. Major investor groups include individuals, securities companies, and foreigners in the Korea Composite Stock Price Index (KOSPI 200) market. The results show that cash market volatility and futures market activity have lead behaviors with one another. However, the contemporaneous variables of cash market volatility and options market activity have only unidirectional causality. Most investors will trade futures and options contracts for speculating within the entire sample period. During political election periods, investors prefer to trade options contracts for hedging rather than futures contracts.     

Discrete hedging of American-type options using local risk minimization

Local risk minimization and total risk minimization discrete hedging have been extensively studied for European options [e.g., Schweizer, M., 1995. Variance-optimal hedging in discrete time. Mathematics of Operation Research 20, 1–32; Schweizer, M., 2001. A guided tour through quadratic hedging approaches. In: Jouini, E., Cvitanic, J., Musiela, M., Option pricing, interest rates and risk management, Cambridge University Press, pp. 538–574]. In practice, hedging of options with American features is more relevant. For example, equity linked variable annuities provide surrender benefits which are essentially embedded American options. In this paper we generalize both quadratic and piecewise linear local risk minimization hedging frameworks to American options. We illustrate that local risk minimization methods outperform delta hedging when the market is highly incomplete. In addition, compared to European options, distributions of the hedging costs are typically more skewed and heavy-tailed. Moreover, in contrast to quadratic local risk minimization, piecewise linear risk minimization hedging strategies can be significantly different, resulting in larger probabilities of small costs but also larger extreme cost.     

Which Traders Contribute Most to Price Discovery? Evidence from the KOSPI 200 Options Market

We examine which group of investors—individuals, institutions, or foreigners—has more information about the true price process in the Korea Stock Price Index 200 (KOSPI 200) options market. Using the Hasbrouck (1995) information share and the Gonzalo and Granger (1995) common factor weight approach, we show that foreigners are the most informative about the efficient price process, and domestic institutional investors as well as individual investors have small contribution to price discovery. This result holds firmly, even after controlling for the effects of trading volume and the number of trades. Our empirical results suggest that foreigners are informed traders in the KOSPI 200 options market, consistent with the findings of Ahn, Kang, and Ryu (2008).