I’m working on a paper with a professor at Stanford about firms’ decisions to adopt and disclose the existence of corporate insiders’ 10b5-1(c) trading plans. In theory, these plans can decrease expected litigation risk for firms and executives, either through reducing the ability to trade on material, non-public information or providing an affirmative defense even for trades that might be of questionable legality. The litigation prophylactic only works, however, if firms disclose the existence of these plans. Based on data that we have collected, many firms that have adopted these plans made no disclosures about this fact. This seems puzzling.