Investor Sentiment and Option Prices

This paper examines whether investor sentiment about the stockmarket affects prices of the S&P 500 options. The findingsreveal that the index option volatility smile is steeper (flatter)and the risk-neutral skewness of monthly index return is more(less) negative when market sentiment becomes more bearish (bullish).These significant relations are robust and become stronger whenthere are more impediments to arbitrage in index options. Theycannot be explained by rational perfect-market-based optionpricing models. Changes in investor sentiment help explain timevariation in the slope of index option smile and risk-neutralskewness beyond factors suggested by the current models.     

Option pricing model with sentiment

In this paper, we develop a closed-form option pricing model with the stock sentiment and option sentiment. First, the model shows that the price of call option is amplified by bullish stock sentiment, and is reduced by stock bearish sentiment, and the price of put option is in the opposite situation. Second, the price of call option is more sensitive to bullish stock sentiment; the price of put option is more sensitive to bearish stock sentiment. Third, the price of call option increases substantially with respect to the stock sentiment and the option sentiment. The price of put option decreases substantially with respect to the stock sentiment, increases substantially with respect to the option sentiment. Fourth, our models also reveal that the option volatility smile is steeper (flatter) when the stock sentiment becomes more bearish (bullish). Finally, stock sentiment and option sentiment lead to the option price deviating from the rational price. The model could offer a partial explanation of some option anomalies: option price bubbles and option volatility smile.     

An examination of U.S. institutional and individual investor sentiment effect on the Turkish stock market

This study examines the effect of rational and irrational components of U.S. institutional and individual investor sentiment on Istanbul Stock Market (ISE) return and volatility. The results show that there is a significant spillover effect of U.S. investor sentiment on stock return and volatility of ISE. A breakdown of sentiment by the type of investor shows that the impact of institutional sentiment is greater than that of individual sentiment. A breakdown of sentiment by rationality shows that the effect of rational sentiment on ISE return is faster though not necessarily greater than that of irrational sentiment. The conclusion from these results is that the effect of U.S. investor sentiment is systemic and cannot be diversified away. U.S. investor sentiment, therefore, constitutes a priced risk factor and must be accounted for accordingly in international asset pricing models. The findings also provide some evidence of a negative relationship between U.S. investor sentiment and ISE return volatility.     

Does Net Buying Pressure Affect the Shape of Implied Volatility Functions?

This paper examines the relation between net buying pressure and the shape of the implied volatility function (IVF) for index and individual stock options. We find that changes in implied volatility are directly related to net buying pressure from public order flow. We also find that changes in implied volatility of S&P 500 options are most strongly affected by buying pressure for index puts, while changes in implied volatility of stock options are dominated by call option demand. Simulated delta‐neutral option‐writing trading strategies generate abnormal returns that match the deviations of the IVFs above realized historical return volatilities.     

Asymmetric information about volatility: How does it affect implied volatility,option prices and market liquidity?

This paper develops a model of asymmetric information in which an investor has information regarding the future volatility of the price process of an asset and trades an option on the asset. The model relates the level and curvature of the smile in implied volatilities as well as mispricing by the Black-Scholes model to net options order flows (to the market maker). It is found that an increase in net options order flows (to the market maker) increases the level of implied volatilities and results in greater mispricing by the Black-Scholes model, besides impacting the curvature of the smile. The liquidity of the option market is found to be decreasing in the amount of uncertainty about future volatility that is consistent with existing evidence. This revised version was published online in June 2006 with corrections to the Cover Date.     

Exploring the relationship between investor sentiment and price volatility

By performing Grey relation analysis, this study elucidates the relationship between investor sentiment and price volatility in the Taiwanese stock market. A sequential relationship is identified between investor sentiment and price volatility, and ranked according to order of importance. Analytical results show that short sales volumes may be an individual leading indicator useful in observing the effects of sentiment on price volatility, followed by open interest put/call ratios and trading volumes, and buy/sell orders. Institutional investors are related, to a lesser extent, to price volatility and sentiment. Qualified foreign institutional investors, or more rational investors, are the least influenced by price volatility, followed by securities investment trust companies and dealers. TAIEX options exert the strongest influence on sentiment during the study period, making them a valuable reference for gauging price volatility.     

Investor sentiment and value and growth stock index options

The paper examines the relationship between both individual and institutional investor sentiment measures and the risk-neutral skewness (RNS) of seven stock index options comprising either growth or value stocks. It provides novel evidence that growth index option prices are affected by sentiment measures. The regression results indicate a significantly positive relationship between sentiment measures and the RNS estimated from four growth index options and a negative relationship with two value index options. The results are economically significant since an associated long–short trading strategy yields high abnormal returns with a Sharpe ratio of up to 1.1 and zero exposure to systematic risk. These high abnormal returns provide evidence of a value premium type anomaly in the index options markets.     

Business Cycles and Net Buying Pressure in the S&P 500 Futures Options

We analyse the cyclical behaviour and intraday pattern of net buying pressure in the S&P 500 futures options market. The results suggest that the net buying pressure of puts is counter‐cyclical and is more intense during contraction periods. The trading profits for selling put options during contraction periods thus far exceed those during expansion periods. Net buying pressure also exhibits an intraday pattern. Trading profits in the early trading sessions are higher than those for the rest of the day. In addition, we show that hourly‐basis hedging yields smaller profits than daily‐basis hedging, which suggests that the trading profits based on daily‐basis hedging may contain a risk premium associated with discretely rebalanced ‘risk‐free’ option portfolios.     

What do insiders know? Evidence from insider trading around share repurchases and SEOs

We examine the nature of information contained in insider trades prior to corporate events. Insiders' net buying increases before open market share repurchase announcements and decreases before seasoned equity offers. Higher insider net buying is associated with better post-event operating performance, a reduction in undervaluation, and, for repurchases, lower post-event cost of capital. Insider trading also predicts announcement returns and long-term abnormal returns following events. Overall, our results suggest that insider trades before corporate events contain information about changes both in fundamentals and in investor sentiment.     

Can margin traders predict future stock returns in Japan?

A growing body of literature suggests that investor sentiment affects stock prices both at the firm level and at the market level. This study examines the relationship between investor behavior and stock returns focusing on Japanese margin transactions using weekly data from 1994 to 2003. Margin trading is dominated by individual investors in Japan. In analysis at the firm level, we find a significant cross-sectional relationship between margin buying and stock returns. Both market-level and firm-level analyses show that margin buying traders follow herding behavior. They seem to follow positive feedback trading behavior for small-firm stocks and negative feedback trading behavior for large firm stocks. Our results show that information about margin buying helps predict future stock returns, especially for small-firm stocks at short horizons. The predictive power does not diminish even after controlling for firm size and liquidity.     

投资者情绪对市场风险价格影响

本文利用我国证券市场统计数据研究了个体和机构投资者情绪对风险市场价格（MPR）的影响,实证结果证明了市场对波动的反应是异质性的,并且受投资者情绪变化的影响。具体来看,将投资者情绪分解成理性和非理性成分后,非理性乐观情绪的增加将导致MPR明显的下降,但理性情绪的变动不会对MPR有明显的影响。这意味着当市场投资者情绪是由基础价值变化来决定的时候,市场风险价格不会发生变化。进一步的VAR脉冲响应函数分析结果显示,非理性的乐观或悲观情绪并不受理性情绪波动的影响,这意味着非理性情绪不是由基础风险因素决定的。     

TESTING THE NET BUYING PRESSURE HYPOTHESIS DURING THE ASIAN FINANCIAL CRISIS: EVIDENCE FROM HANG SENG INDEX OPTIONS

We investigate net buying pressure in the Hong Kong Hang Seng Index options market during the Asian financial crisis from July 1997 to August 1998. Our findings suggest that during this period, the dramatic changes in volatility overwhelmed the dynamics of supply and demand in the options market. The extremely high realized volatility drove market participants' expectations about future market volatility in the early months of the crisis. Findings during the late‐crisis, pre‐crisis, and post‐crisis periods are consistent with the net buying pressure hypothesis.     

Investor Sentiment and Return Predictability of the Option to Stock Volume Ratio

We study the effect of investor sentiment on the relation between the option to stock volume ratio (O/S) and future stock returns. Relative option volume has return predictability under short sale constraints. For this reason, we expect and find a stronger O/S‐return relation during high sentiment periods than during low sentiment periods. We find that Baker and Wurgler's Investor Sentiment Index affects the O/S‐return relation after controlling for consumer sentiment indices and economic environment factors. While prior studies have used consumer sentiment indices as alternative measures of investor sentiment, our results suggest these effects are distinct.     

Options Trading Based on the Forecasting of Volatility Direction with the Incorporation of Investor Sentiment

Using options price data on the Taiwanese stock market, we propose an options trading strategy based on the forecasting of volatility direction. The forecasting models are constructed with the incorporation of absolute returns, heterogeneous autoregressive-realized volatility (HAR-RV), and proxy of investor sentiment. After we take into consideration the margin-based transaction costs, the results of our simulated trading indicate that a straddle trading strategy that considers the forecasting of volatility direction with the incorporation of market turnover achieves the best Sharpe ratios. Our trading algorithm bridges the gap between options trading, market volatility, and the information content of investor overreaction.     

Asset pricing with investor sentiment: On the use of investor group behavior to forecast ASEAN markets

A study of investor behavior, using four investor groups (local, foreign, institutional, and dealer's accounts) on the Stock Exchange of Thailand (SET). The daily net purchases of each group are used as leading indicators for sentiment. The sentiments are examined with relation to each other and market returns. Eight proven macroeconomic factors with known cross-sectional relationships and known to forecast with returns are examined as a benchmark for the newly proposed sentiment factor model. Retesting the factors allows for an apples to apples comparison with the proposed sentiment factors. Using a VAR framework this research finds that dealers predominantly sell to institutional accounts, creating a negative correlation between the two groups, in addition to strong institutional herding which is all indicative of potential agency problems on the exchange. Also find that local individual accounts practice negative feedback trading and the other groups practice positive feedback trading. Of the four groups, the only group that influences the SET is the local individual group of investors. The foreign investor is found to be the least significant group on market returns, provide market liquidity to locals, and be the least responsive to daily market changes-following the prudent man rule. Lastly, propose a simple model, using investor behavior to accurately predict the market's direction for the following day 76 percent of the time with market timing ability (66 percent in Malaysia). This can be useful for buying and shorting the market.     

Asymmetric Volatility and Trading Activity in Index Futures Options

We examine the impact of option trading activity on implied volatility changes to returns in the index futures option market. Controlling for option moneyness, delta‐to‐option‐premium ratio, and liquidity, we find that net buying pressure, profit‐maximization behavior, and liquidity are interrelated and affect asymmetric responses of implied volatilities to returns. Implied volatilities of options with more liquidity, a higher exercise price, and a higher delta‐to‐option‐premium ratio have the most profound asymmetric response.     

Investor sentiment and the underperformance of technology firms initial public offerings

This research examines the effect of individual and institutional investor sentiment toward the overall market at the time of Initial Public Offering (IPO) on the aftermarket performance of technology IPO shares. The study which is based on 1346 U.S. technology IPOs completed between 1992 and 2009 shows that the irrational component of individual investor sentiment negatively affects shares’ aftermarket performance: the more optimistic individual investors are at the time of IPO, the lower the shares’ aftermarket return. On the other hand, the rational component of institutional investor sentiment does not affect the shares’ short-run performance, yet positively affects their long-run performance. In contrast with prior theoretical models this paper shows that investor overconfidence positively affects technology IPO shares’ aftermarket performance. The paper extends the behavioral finance literature by providing evidence on the negative role played by noise trading in affecting technology and biotechnology IPO shares performance.     

Keep on smiling? The pricing of Quanto options when all covariances are stochastic

The paper introduces a model for the joint dynamics of asset prices which can capture both a stochastic correlation between stock returns as well as between stock returns and volatilities (stochastic leverage). By relying on two factors for stochastic volatility, the model allows for stochastic leverage and is thus able to explain time-varying slopes of the smiles. The use of Wishart processes for the covariance matrix of returns enables the model to also capture stochastic correlations between the assets. Our model offers an integrated pricing approach for both Quanto and plain-vanilla options on the stock as well as the foreign exchange rate. We derive semi-closed form solutions for option prices and analyze the impact of state variables. Quanto options offer a significant exposure to the stochastic covariance between stock prices and exchange rates. In contrast to standard models, the smile of stock options, the smile of currency options, and the price differences between Quanto options and plain-vanilla options can change independently of each other.     

The price of a smile: hedging and spanning in option markets

The volatility smile changed drastically around the crash of1987, and new option pricing models have been proposed to accommodatethat change. Deterministic volatility models allow for moreflexible volatility surfaces but refrain from introducing additionalrisk factors. Thus, options are still redundant securities.Alternatively, stochastic models introduce additional risk factors,and options are then needed for spanning of the pricing kernel.We develop a statistical test based on this difference in spanning.Using daily S&P 500 index options data from 1986-1995, ourtests suggest that both in- and out-of-the-money options areneeded for spanning. The findings are inconsistent with deterministicvolatility models but are consistent with stochastic modelsthat incorporate additional priced risk factors, such as stochasticvolatility, interest rates, or jumps.     

投资者情绪、期权隐含信息与股市波动率预测——基于上证50ETF期权的经验研究

在异质自回归模型(HAR-RV)中引入中国上证50ETF期权隐含信息和投资者情绪,本文分别对中国股票市场未来日、周和月波动率进行预测。研究发现,期权隐含信息和投资者情绪能够提高HAR-RV模型对股票市场未来波动率的预测效果。投资者情绪对未来波动率的影响存在两种机制:在情绪高涨期间,月已实现波动率与未来波动率正相关,说明以个人投资者占主体所引起的价格信息机制,在中国股票市场交易中占主导作用;风险中性偏度与未来波动率负相关,说明以个人投资者占主体所引起的噪声交易机制占主导作用。