Expiration-day effect: evidence from high-frequency data in the Hong Kong stock market

By employing high-frequency data, a series of minute-by-minute HSI data, this paper examines whether the expiration-day effect exists in the last trading period before the market closes in the Hong Kong stock market. Contrary to the previous findings in the well-developed US markets, this paper finds that the expiration-day effect neither exists on the whole expiration day nor in the last trading time of the expiration day before the market closes. This study suggests that the expiration-day effects are not unavoidable by-products of the creation of index futures in the stock market.