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. Copyright 2005 by the Eastern Finance Association.