I know people who have worked in corporate acquisitions and there are a ton of controls in place to limit information access and prevent the mere appearance of privelged information being used for personal gain. Likewise in other industries like utilities there are pretty complex regulations to prevent companies from getting even a few cents per kilowatt hour advantage, etc. and all this shit has multimillion dollar fines attached.
Congress could definitely adopt a rule that bans trading stocks for anyone who receives classified or nonpublic industry-specific information as part of security briefings or their committee assignments. Or hell, just limit congresspeople to index funds or generic portfolios managed by external fiduciaries, while in office.
It seems that if both Gaetz/Cruz types and AOC agree on this, they could get it done, but the establishment politicians don’t want to because they view it as a perk of the job.