Intra Day Bid‐Ask Spreads, Trading Volume and Volatility: Recent Empirical Evidence from the London Stock Exchange

Abstract

With the benefit of very high frequency (25 million 1 minute observations) and recent data (2001) for the UK, this paper explores a number of intra day patterns of stock market behaviour. More specifically, a distinct reverse J shaped bid‐ask spread pattern is noted for SETS securities, a declining bid‐ask spread pattern for non‐SETS securities, a two hump pattern for trading volume and a U‐shaped pattern for returns volatility for all securities. In terms of complementing the existing literature, the paper shows that differences in trading systems may affect the bid‐ask spread patterns, while differences in market environments (i.e. US and UK markets) seems to affect the trading volume pattern. The paper suggests avenues for future research, in particular, the need to consider what factors are significant in determining intra day patterns for different trading systems and the need for additional cross‐market comparisons to identify how institutional factors affect the behaviour of investors on an intra day basis.