This study examines the effects of financial reporting complexity on investors’ trading behavior. I find that more complex (longer and less readable) filings are associated with lower overall trading, and that this relationship appears due to a reduction in small investors’ trading activity. Additional evidence suggests that the association between report complexity and lower abnormal trading is driven by both cross-sectional variation in firms’ disclosure attributes and variations in disclosure complexity over time. Given regulatory concerns over plain English disclosures and the trend toward more disclosure, my investigation into the effects of reporting complexity on small and large investors should be of interest to regulators concerned with reporting clarity and leveling the playing field across classes of investors.

We examine the first significant deregulation of U.S. disclosure requirements since the passage of the 1933/1934 Exchange and Securities Acts: the 2007 Securities and Exchange Commission (SEC) Rule 12h-6. Rule 12h-6 has made it easier for foreign firms to deregister with the SEC and thereby terminate their U.S. disclosure obligations. We show that the market reacted negatively to the announcement by the SEC that firms from countries with weak disclosure and governance regimes could more easily opt out of the stringent U.S. reporting and legal environment. We also find that since the rule's passage, an unprecedented number of firms have deregistered, and these firms often had been previous targets of U.S. class action securities lawsuits or SEC enforcement actions. Our findings suggest that shareholders of non-U.S firms place significant value on U.S. securities regulations, especially when the home country investor protections are weak.