We examine insider trades of bankers as a measure of how much they know relative to outsiders. In contrast to trades of insiders in non-financial firms, trades by bankers are less informative. Although bankers are relatively better at timing their sales, they earn negative long-run abnormal returns on their purchases. This is in marked contrast to insiders in non-financial firms. Although banks are more opaque during the crisis, bank insider trades are still relatively uninformative during this period. These results are not driven by differences in firm size, liquidity or governance and compensation structures. Our results suggest that even if banks are transparent according to many standard measures, they are difficult to understand-even for insiders.