Insider trading is not illegal for members of Congress...that is absolutely true. Congress exempted themselves from that legislation.
Tell that to the first member of Congress to endorse Donald Trump for president. “Former Rep. Chris Collins Sentenced to 26 Months in Prison”
New York politician had plead guilty to insider trading charges and resigned in October”
https://www.wsj.com/articles/former-rep-chris-collins-sentenced-to-26-months-in-prison-11579303078