STOCK-MARKET MICROSTRUCTURE AND RETURN VOLATILITY - EVIDENCE FROM ITALY

This paper studies the impact of the stock market microstructure on return volatility and on the value discovery process in the Milan Stock Exchange. The primary trading mechanism employed by this exchange is a call market, which is usually preceded and followed by trading in a continuous market. We find that the opening transaction in the continuous market has the highest volatility, and that opening the market with the call transaction seems to produce relatively lower volatility. In the closing transaction, investors correct perceived errors or noise in the prices set at the call. The implications of the results for market design are examined. © 1990.