Until recently Congresspeople and senators legally did insider trading

Likely from 1776 until Congress voted to make this illegal Congresspeople and Senators benefited from insider trading until the last few years. But, the problem with this is likely you won't see poorer Congresspeople and Senators being elected in the future because of this. Because it was a useful perk to incentivize Congress people in general to speak and to raise money to become a member of congress because the success this could bring them through insider trading. Now you probably won't see poorer men and women trying to become Senators and Congress people as a result. So, even though it is more honest to have this law it also will prevent poorer people from ever becoming members of congress.

So, we likely will see more and more really rich billionaires in Congress and even as president more like Trump is.

Presidents (as far as I know) never benefited from insider trading. They benefit mostly from writing books and paid public speaking after they leave office. Some ex-president's and their wives do very well with this.

When a president enters office all his or her wealth goes into a "Blind Trust" so they are not allowed to manipulate their earnings in any way after they enter office. This makes a president act in more neutral ways regarding their income and also they are well paid as presidents too.

I wrote this all after saying that the Chinese market is a victim of insider trading which makes it a bad investment for most foreigners because of this. And insider trading is done mostly by the upper echelon of the Chinese Communist party. However, I wanted people around the world also to know that insider trading also has existed in the past legally by the U.S. Congress.

Also, Congresspeople also benefit a lot after they retire from Congress by being Lobbyists for large corporations. Sine they have many friends and business acquaintances among congressional people and presidents they often can turn this into great wealth for corporations after they leave office.

One of the most notable is Vice President Dick Cheney who was and likely still is a lobbyist for Halliburton which is a war munitions corporation especially during the Iraq and Afghanistan wars.

However, this sort of thing is very common among retired Government officials here in the U.S.