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.     

Expected Time Value Decay of Options: Implications for Put‐Rolling Strategies

Assuming the underlying asset price remains constant, previous studies show that the time value of an option decays gradually at a rate that accelerates over time and peaks at the expiration date. Thus, a significant portion of time value is lost in the four weeks leading up to expiration. This paper shows the time value of currently at‐ or near‐the‐money options should be expected to decay at a rate that decreases over time. The time values of options that are currently deep‐in‐ or deep‐out‐of‐the‐money are expected to initially rise and then resume the normal decay pattern.     

Price discovery of credit spreads in tranquil and crisis periods

In this paper we investigate the price discovery process in single-name credit spreads obtained from bond, credit default swap (CDS), equity and equity option prices. We analyse short term price discovery by modelling daily changes in credit spreads in the four markets with a vector autoregressive model (VAR). We also look at price discovery in the long run with a vector error correction model (VECM). We find that in the short term the option market clearly leads the other markets in the sub-prime crisis (2007–2009). During the less severe sovereign debt crisis (2009–2012) and the pre-crisis period, options are still important but CDSs become more prominent. In the long run, deviations from the equilibrium relationship with the option market still lead to adjustments in the credit spreads observed or implied from other markets. However, options no longer dominate price discovery in any of the periods considered. Our findings have implications for traders, credit risk managers and financial regulators.     

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 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.     

Finance, Politics, and the Accounting for Stock Options

The politics of option accounting crosses party lines, reflecting both the interests of the affected constituencies and the desire for power over standard setting. House Bill HR-3574, which mandates an assumption of zero stock price volatility, runs counter to the recently passed Financial Accounting Standards Board (FASB) rule requiring fair-value expensing of stock options. For any option issued at or out of the money, where strike prices are normally set, expense recognition is zero under this bill's mandated assumption.
Besides excessive use of stock options, the lack of a "final peace" in the option accounting war appears to have encouraged another questionable corporate practice. This article examines a sample of "six-and-one restructurings," exchanges of options in which expensing of re-priced (deep out-of-the-money) options can be avoided if employees wait at least six months and one day before receiving new options. The authors found that market-adjusted stock prices tend to decrease during the six-month period before the strike price is reset. This result provides one more reason why companies should be required to use fair-value option pricing models to expense options.     

Short‐Selling Bans Around the World: Evidence from the 2007–09 Crisis

Most regulators around the world reacted to the 2007–09 crisis by imposing bans on short selling. These were imposed and lifted at different dates in different countries, often targeted different sets of stocks, and featured varying degrees of stringency. We exploit this variation in short‐sales regimes to identify their effects on liquidity, price discovery, and stock prices. Using panel and matching techniques, we find that bans (i) were detrimental for liquidity, especially for stocks with small capitalization and no listed options; (ii) slowed price discovery, especially in bear markets, and (iii) failed to support prices, except possibly for U.S. financial stocks.     

Is there price discovery in equity options?

We use tick-by-tick quote data for 39 liquid US stocks and options on them, and we focus on events when the two markets disagree about the stock price in the sense that the option-implied stock price obtained from the put-call parity relation is inconsistent with the actual stock price. Option market quotes adjust to eliminate the disagreement, while the stock market quotes behave normally, as if there were no disagreement. The disagreement events are typically precipitated by stock price movements and display signed option volume in the direction that tends to eliminate the disagreements. These results show that option price quotes do not contain economically significant information about future stock prices beyond what is already reflected in current stock prices, i.e., no economically significant price discovery occurs in the option market. We also find no option market price discovery using a much larger sample of disagreement events based on a weaker definition of a disagreement, which verifies that the findings for the primary sample are not due to unusual or unrepresentative market behavior during the put-call parity violations.     

The Lead‐Lag Relationship Between Cash and Stock Index Futures in a New Market

This paper investigates the lead‐lag relationship in daily returns and volatilities between price movements of the FTSE/ATHEX‐20 and FTSE/ATHEX Mid‐40 stock index futures and the underlying cash indices in the relatively new futures market of Greece. Empirical results show that there is a bi‐directional relationship between cash and futures prices. However, futures lead the cash index returns, by responding more rapidly to economic events than stock prices. This speed is much higher in the more liquid FTSE/ATHEX‐20 market. Moreover, results indicate that futures volatilities spill information over to the corresponding cash market volatilities in both investigated futures markets, but volatilities in the cash markets have no effect on the volatilities of futures markets. Overall, it seems that new market information is disseminated faster in the futures market compared to the stock market. This implies that the futures markets can be used as price discovery vehicles, providing further evidence that derivatives markets contribute to completing and stabilising capital markets in Greece. A further finding of this study is that futures volume and disequilibrium effects between cash and futures prices are important variables in the explanation of volatilities in cash and futures markets.     

THE PRICING AND HEDGING OF LIMITED EXERCISE CAPS AND SPREADS

Capped options are barrier option spreads that automatically create simultaneous long and short positions. Exchange-traded capped options were introduced in 1991, though with limited volume. Such options, however, have traded on the over-the-counter markets for several years. Most of these options have the unusual feature that they automatically exercise when the underlying asset closes beyond a critical strike, making them a hybrid of European and American options. In this paper I present their boundary conditions and examine the prices, deltas, gammas, and thetas of caps as well as spreads constructed with European and American options. I also examine the effect of permitting exercise based only on the closing price as opposed to exercise at any time the critical strike is reached. I show that assuming that exercise can occur at any time can lead to serious pricing errors. The results have implications for the pricing of barrier options in general, which nearly always exercise early based only on the closing price.     

Options and efficiency: Some experimental evidence

This paper examines the information aggregation role of options when agents possess diverse information about possible asset returns. We construct two identical experimental markets: one with and one without options. We find that options speed the information aggregation process. Asset markets that have parallel option markets aggregate traders' diverse information faster than markets where options trading is not available. Implied ranges were calculated from asset and option prices and compared to the actual ranges. These comparisons suggest that options may provide a means for agents to coordinate beliefs about asset values.     

What Type of Process Underlies Options? A Simple Robust Test

We develop a simple robust method to distinguish the presence of continuous and discontinuous components in the price of an asset underlying options. Our method examines the prices of at‐the‐money and out‐of‐the‐money options as the option's time‐to‐maturity approaches zero. We show that these prices converge to zero at speeds that depend upon whether the underlying asset price process is purely continuous, purely discontinuous, or a combination of both. We apply the method to S&P 500 index options and find the existence of both a continuous component and a jump component in the index.     

Ripples through markets: Inter-market impacts generated by large trades

This paper uses a sample of large trades executed on the London Stock Exchange's SEAQ-I market for European cross-traded firms to investigate their impact on home market prices when parallel markets suffer from information frictions. I find that (a) large London trades produce price impacts in home markets even though no timely information is published, (b) market makers appear to pre- and post-position their inventories by splitting orders across markets, and (c) the price discovery process across markets changes significantly around large trades with the foreign market making a significantly bigger contribution to price discovery at this time, even though information opaqueness exists.     

Cross-sectional tests of deterministic volatility functions

We study the cross-sectional performance of option pricing models in which the volatility of the underlying stock is a deterministic function of the stock price and time. For each date in our sample of FTSE 100 index option prices, we fit an implied binomial tree to the panel of all European style options with different strike prices and maturities and then examine how well this model prices a corresponding panel of American style options. We find that the implied binomial tree model performs no better than an ad-hoc procedure of smoothing Black–Scholes implied volatilities across strike prices and maturities. Our cross-sectional results complement the time-series findings of Dumas et al. [J. Finance 53 (1998) 2059].     

Analytical pricing of American options

By using the homotopy analysis method, we derive a new explicit approximate formula for the optimal exercise boundary of American options on an underlying asset with dividend yields. Compared with highly accurate numerical values, the new formula is shown to be valid for up to 2?years of time to maturity, which is ten times longer than existing explicit approximate formulas. The option price errors computed with our formula are within a few cents for American options that have moneyness (the ratio between stock and strike prices) from 0.8 to 1.2, strike prices of 100 dollars and 2?years to maturity.     

Modeling stock pinning

This paper investigates the effect of hedging strategies on the so-called pinning effect, i.e. the tendency of stock's prices to close near the strike price of heavily traded options as the expiration date nears. In the paper we extend the analysis of Avellaneda and Lipkin, who propose an explanation of stock pinning in terms of delta hedging strategies for long option positions. We adopt a model introduced by Frey and Stremme and show that, under the original assumptions of the model, pinning is driven by two effects: a hedging-dependent drift term that pushes the stock price toward the strike price and a hedging-dependent volatility term that constrains the stock price near the strike as it approaches it. Finally, we show that pinning can be generated by simulating trading in a double auction market. Pinning in the microstructure model is consistent with the Frey and Stremme model when both discrete hedging and stochastic impact are taken into account.     

INFORMATION AND NOISE IN FINANCIAL MARKETS: EVIDENCE FROM THE E‐MINI INDEX FUTURES

I examine the informational contributions and effects on transitory volatility of trades initiated by different types of traders in three actively traded index futures markets. The results show that trades initiated by exchange member firms account for more than 60% of price discovery during the trading day. These institutional trades appear to be more informative than trades of individual exchange members or off‐exchange traders. I also find that off‐exchange traders introduce more noise into the prices than do exchange members. My findings provide new evidence on the role of different types of traders in the price formation process.     

Are options redundant? Further evidence from currency futures markets

This paper investigates the impact of the introduction of options on the underlying asset's price formation process, using Geweke feedback measures. We derive the feedback measures from the Deutsche Mark, British Pound, Swiss Franc, Japanese Yen and Canadian Dollar futures and spot prices, before and after the introduction of options for these currency futures. While each currency market maintains some distinct characteristics in the post-option period, a common theme is found: after the option introduction, the instantaneous feedback between spot and futures markets improves drastically. The feedback from the spot to the futures market tends to decrease and remains small. The feedback from the futures market to the spot market tends to decrease as well. These results confirm the dominance of options markets, probably due to their smaller transaction costs. When made available, options assume a leading role for information transmission in currency markets.     

Welfare‐increasing third‐degree price discrimination

When demand functions in different markets are derived from distributions of reservation prices that differ only in their means, conditions exist such that third‐degree price discrimination leads to greater total output and greater total welfare. Welfare is higher with discrimination than with a uniform price when demand functions are derived from logistic distributions with different means. Welfare and consumer surplus are higher with discrimination for demands derived from a distribution related to the Pareto. In general, whether discrimination increases total output depends on demand being more convex in markets in which prices fall with discrimination than in those in which prices rise.     

News‐Specific Price Discovery in Credit Default Swap Markets

We examine the lead and lag relation between equity and credit default swap (CDS) markets. We find that price discovery in equity markets only leads CDS markets following aggregate positive news and not so following other news. While difficult to reconcile with standard asset pricing theories, asymmetric price adjustment is common in goods markets, arising from intermediary power. We provide an explanation for this asymmetry based on dealers exploiting informational advantages vis‐à‐vis investors with hedging motives. Consistent with this explanation, we find that the patterns we document are related to firm‐level proxies for hedging demand, as well as economy‐wide measures of information asymmetries.