Passive Informed Trading Around Earnings Announcements

Using a sample of NASDAQ firms we investigate informed trading in the limit order book (LOB) prior to earnings announcements. Consistent with recent limit order theory, and in contrast to classic adverse selection models, we show that informed traders supply liquidity. Relative to a sample of low-shock announcements as a control, we find that for high-shock firms, the spread is lower, the correlation of bid and ask depth is higher, the implied cost of trading is lower, and the information share of component of the limit order book is higher, relative to low-shock earnings announcements