Members of Congress can legally trade individual stocks — but under the 2012 STOCK Act they must publicly disclose most trades within 45 days. That disclosure is what makes tracking them possible.
The penalty for a member of Congress filing a late stock-trade disclosure is often just a $200 fine — small enough that some pay it repeatedly rather than report on time.
In the 12 months ending 2026-07-09, members of Congress disclosed more trades in MSFT than in any other stock — 12 separate buy or sell disclosures under the STOCK Act.