They simply have access to too much information. Everything they and their spouse or partner own should be in a blind trust from the time they win a primary election until they've been out of office for some set period of time, say 10 years, since the information they get especially on committees related to the treasury, commerce, and national intelligence, has impacts lasting years.
It should be impossible to go from a nobody to achieving generational wealth in a decade due to legally protected insider trading. Trading is zero sum - someone sold those NVDA calls to Pelosi and lost millions. Information asymmetry just makes this legally protected theft with extra steps.