Regulators around the world often express concerns about the high volatility of stock markets due to index derivative expirations. Earlier studies of expiration day effects have found large volume effects, abnormal return volatility, and price effects during the last hour of trading on expiration days when the settlement is based on the closing price. This article examines the impact of the expiration of Hang Seng Index (HSI) derivatives on the underlying cash market in Hong Kong for the period from 1990 to 1999. The HSI derivative market is different from most other markets in the sense that the settlement price is computed by taking the average of 5-minute quotations of the HSI on the last trading day, thus providing an alternative setting for testing expiration day effects. Our empirical findings indicate that expiration days in Hong Kong may be associated with a negative price effect and some return volatility on the underlying stock market,

In this article, we study the empirical performance of the GARCH option pricing model relative to the ad hoc Black-Scholes (BS) model of Dumas, Fleming, and Whaley. Specifically, we investigate the empirical performance of the option pricing model based on the exponential GARCH (EGARCH) process of Nelson. Using S&P 500 options data, we find that the EGARCH model performs better than the ad hoc BS model both in terms of in-sample valuation and out-of-sample forecasting. However, the superiority of out-of-sample performance EGARCH model over the ad hoc BS model is small and insignificant except in the case of deep-out-ofmoney put options. The out-performance diminishes as one lengthens the forecasting horizon. Interestingly, we find that the more complicated

This study examines the intraday trading activities of index stocks on the common expiration day of index derivatives. In Hong Kong, index futures and index options use an Asian-style settlement procedure. All contracts are settled against the estimated average settlement price, an arithmetic average of the underlying cash index taken every five minutes on the expiration day. Trading volume and total trade count on the expiration day are both found to be higher than normal. Most important, trading intensifies in terms of volume and frequency close to the five-minute time marks. The study does not find significant price reversal and price compression patterns. Although significant order imbalance pattern is found on some expiration days, the results show no association between order imbalance pattern and the next-day return.

No abstract

No abstract