Volume and Autocovariances in Short-Horizon Individual Security Returns

This article tests for the relations between trading volume and subsequent returns patterns in individual securities' short-horizon returns that are suggested by such articles as Blume, Easley, and O'Hara (1994) and Campbell, Grossman, and Wang (1993) . Using a variant of Lehmann's (1990) contrarian trading strategy, we find strong evidence of a relation between trading activity and subsequent autocovariances in weekly returns. Specifically, high-transaction securities experience price reversals, while the returns of low-transactions securities are positively autocovarying. Overall, information on trading activity appears to be an important predictor of the returns of individual securities.     

Stock Market Declines and Liquidity

Consistent with recent theoretical models where binding capital constraints lead to sudden liquidity dry-ups, we find that negative market returns decrease stock liquidity, especially during times of tightness in the funding market. The asymmetric effect of changes in aggregate asset values on liquidity and commonality in liquidity cannot be fully explained by changes in demand for liquidity or volatility effects. We document interindustry spillover effects in liquidity, which are likely to arise from capital constraints in the market making sector. We also find economically significant returns to supplying liquidity following periods of large drops in market valuations.