For models of the probability of informed trading (PIN), estimation can fail for firms with high levels of trading due to computer over/under-flow. Since active firms tend to have large market capitalizations, studies that use PIN have excluded as much as 40% of total market capitalization from...

We find that a substantial portion of short sellers' trading advantage comes from their ability to analyze publicly available information. Using a database of short sales combined with a database of news releases, we show that the well-documented negative relation between short sales and future...