The AMEX changed the tick size from[formula]to[formula]for low-price stocks on September 3, 1992. Consistent with the prediction of L. E. Harris (1994, Minimum price variations, discrete bid–ask spreads, and quotation sizes,Rev. Finan. Stud.7,149–178), the change has reduced both quoted and effective spreads, although the magnitude of the reduction is much smaller than predicted. However, we fail to find evidence of a significant increase in trading volume. Our cross-sectional regressions show that stocks with greater trading activity, lower prices, and stronger competition from the regional exchanges experienced greater spread reductions.Journal of Economic LiteratureClassification Numbers: G10, G18, G20.

We test the hypothesis that insider trading impairs market liquidity by analyzing intraday trades and quotes around 1,497 IPO lockup expirations in the period 1995–1999. We find that, while lockup expirations are associated with considerable insider trading for some IPO firms, they have little effect on effective spreads. By contrast, two other liquidity measures, quote depth and trading activity, improve substantially. In the 23% of lockup expirations where insiders disclose share sales, spreads actually decline. These findings indicate that a large body of well-informed, blockholding insider traders can enter a market from which they had previously been absent, and substantially change trading volume and share price without impairing market liquidity.

This paper examines the impact of share repurchase tender offers on the market microstructure. We find that there is a temporary reduction in the bid–ask spread, and a temporary increase in volume and quotation depth during the offer period. Our evidence suggests that the bid–ask spread is asymmetric during the offer period with the bid-side spread smaller than the ask-side spread. The temporary reduction in the spread around offers is consistent with the competing-market-maker hypothesis which predicts that the intensified competition for the market maker raises bid prices and narrows the spread asymmetrically during the offer period.

This paper studies Nasdaq market makers' activities during the one and one‐half hour preopening period. Price discovery during the preopening is conducted via price signaling as opposed to the auction used to open the NYSE or the continuous market used during trading. In the absence of trades, Nasdaq dealers use crossed and locked inside quotes to signal to other market makers which direction the price should move. Furthermore, we find evidence of price leadership among market makers that bears little resemblance to their IPO/SEO lead underwriter participation.

This article tests for differences in execution costs among specialist firms for New York Stock Exchange listed securities. Execution cost differences provide a measure of the relative performance of specialist firms. We find a substantial difference in effective spreads and order processing costs across specialist firms, controlling for stock characteristics. While economically significant, the differences in execution costs between specialist firms are much smaller than the cross‐market differences reported by Huang and Stoll (1996). Within a specialist firm, there is a positive relation between order processing costs and trading activity that is consistent with the hypothesis that active stocks subsidize inactive stocks.

We examine in an event-study context what factors affect the relative performance of stocks during liquidity crises. We find that market risk, measured by the market beta, is not a good measure of expected abnormal stock returns on days with liquidity crises. Instead, abnormal stock returns during liquidity crises are strongly negatively related to liquidity risk, measured by the co-movement of stock returns with market liquidity. The degree of informational asymmetry and the ownership structure of the firm also help to explain abnormal stock returns on crisis days. Our findings have important implications for managing the liquidity risk of equity portfolios.