Hallerbach (2004) derives an approximation formula to compute a Black-Scholes implied volatility. This formula is equivalent to equation (7) in Corrado and Miller (1996a), with the substitution of a geometric average of stock and strike prices in place of an arithmetic average. Ceteris paribus...

We examine the forecast quality of Chicago Board Options Exchange (CBOE) implied volatility indexes based on the Standard and Poor's 100 and Nasdaq 100 stock indexes. We find that the forecast quality of CBOE implied volatilities for the Samp;P 100 (VIX) has significantly improved in recent...

The academic literature generally concludes that the Black-Scholes model overstates the value of employee stock options (ESOs). In particular, because ESOs cannot be traded, employee risk aversion often elicits premature exercise. As a result, the ESO is less valuable than a traded option. An...

We examine market efficiency before and after the 1987 Market Crash using the box spread strategy implemented with European-style S&P 500 Index (SPX) options. Before the Crash, apparent arbitrage opportunities were rare and simulated trades were unprofitable assuming a one-minute execution...

We analyze the intra-week evolution of bookie-quoted National Football League betting lines in New York City and its implications for market efficiency. Our unique data set includes three sequential lines: (i) an outlaw line set by a single agent at the beginning of the week; (ii) Tuesday's...