The Intraday Pattern of Information Asymmetry, Spread, and Depth: Evidence from the NYSE

Studies suggest that investment flows, liquidity imbalances, and institutional trading may create intraday trading patterns and opportunities for investors to time their trades to reduce transaction costs. Motivated by these studies, we divide each trading day into 13 half-hour trading intervals and measure information asymmetry from price changes, trade sizes, and trade directions. We find that information asymmetry starts high in the morning, drops continuously until it reaches a midday low during Interval 7, rises to a midday high during Interval 10, and drops continuously after. In contrast, neither the spread nor the depth exhibit similar midday extreme values. Essentially, we identify a 90-min window in the afternoon when net valuable information arrives to the market in high frequency while liquidity is stable, and that may be an opportunity for some investors to time their trades. In addition, we show that market makers employ dynamic strategies that change the spread, the depth, or both to manage information asymmetry. This is particularly evident during the last three trading intervals, where the significant drop in information asymmetry is countered primarily by a significant increase in the depth while the spread is almost constant.