Abstract: A 2004 study of the results of stock trading by United States Senators during the 1990s found that that Senators on average beat the market by 12% a year. In sharp contrast, U.S. households on average underperformed the market by 1.4% a year and even corporate insiders on average beat the market by only about 6% a year during that period. A reasonable inference is that some Senators had access to – and were using – material nonpublic information about the companies in whose stock they trade.
Under current law, it is unlikely that Members of Congress can be held liable for insider trading. The proposed Stop Trading on Congressional Knowledge Act addresses that problem by instructing the Securities and Exchange Commission to adopt rules intended to prohibit such trading.