The Stop Trading on Congressional Knowledge (STOCK) Act of 2012 is a United States federal law that prohibits insider trading by members of Congress, executive branch employees, and judicial officers, and requires disclosure of financial transactions to prevent conflicts of interest. Enacted to address concerns that lawmakers were profiting from non-public information obtained through their official duties, the Act explicitly applies insider trading prohibitions under securities laws, including the Securities Exchange Act of 1934 and Rule 10b-5, to all federal government personnel. It mandates that members of Congress and certain high-level employees disclose financial transactions, such as stock trades, within 30 days, a significant change from the previous annual reporting requirement. The law also confirms amendments to the Commodity Exchange Act to extend these protections against trading on material nonpublic information.

The STOCK Act passed with overwhelming bipartisan support, clearing the Senate 96-3 in February 2012 and the House 417-2 shortly thereafter, before being signed into law by President Barack Obama on April 4, 2012. It was driven by public outrage over reports of congressional members outperforming the stock market, fueled by scandals like the 2008 financial crisis where lawmakers allegedly used privileged information. While the Act introduced penalties for violations and enhanced transparency, it has faced criticism for lacking enforcement mechanisms and not going far enough to curb influence peddling. Subsequent legislative efforts, such as bills to ban individual stock trading by Congress members or mandate blind trusts, have been proposed but not enacted as of 2025, with renewed calls amid market volatility linked to policy decisions under President Trump.

Overall, the STOCK Act represents a key step in government ethics reform, though its effectiveness remains debated. Investigations and reports continue to highlight instances of potential violations, underscoring ongoing challenges in regulating financial activities of public officials.