Two Democrat lawmakers plan to introduce today a bill that would block trading on such inside information. Current securities law and congressional ethics rules don't prohibit lawmakers or their staff members from buying and selling securities based on information learned in the halls of Congress. . . .

In addition to banning trading on inside information, the proposal would require that lawmakers and their top aides disclose within 30 days any stock trades. Congressional rules now require lawmakers to disclose their trades once a year. . . .

To some extent, the legislation would expand the commonly used definition of insider trading. According to the Securities and Exchange Commission, insider trading is the buying or selling of securities on the basis of material, nonpublic information in violation of a duty. But the information in question normally comes from inside a company: For example, an executive of a publicly traded company can't tell friends to sell company stock if he or she knows that the company is about to fall short of its quarterly earnings forecast.

Lawmakers and staff members never have faced similar obligations on the information they acquire. "If a congressman learns that his committee is about to do something that would affect a company, he can go trade on that because he is not obligated to keep that information confidential," said Thomas Newkirk, a partner with law firm Jenner & Block LLP and a former official with the SEC's enforcement division. "He is not breaching a duty of confidentiality to anybody and therefore he would not be liable for insider trading."

Am I alone in wondering why some rules of business the rest of us take for granted don’t apply to Congress?