Congress traditionally exempts itself from the federal laws it issues governing the rest of us. The high-minded reason is that it prevents members from unwarranted interference from the executive branch, thereby preserving their status as a co-equal branch of government.
A less high-minded reason? You can make a killing with non-public information on the stock market.
Both parties get away with this – a bill to prevent members from doing so died with only six co-sponsors – but for sheer brazenness it’s hard to beat the former madame Speaker of the House, whose “face melts” during a Q&A session at the 09:20 mark on the embedded video at the link.