Is there potential for the President of the United States to commit insider trading? Certainly. The President has access to all kinds of material information that is non-public, either because it’s classified, confidential, or not yet cleared for public consumption.
Some examples of material information that the President could have access to before the general public:
- Knowledge of the progress of trade talks (Have we made a breakthrough? Is the other side insisting on something that we’re never going to accept? Is this negotiation a priority for the administration, or will we drop it if we don’t get a great deal?)
- More critically, what is actually in these deals, before they’ve been publicly released? What concessions were extracted? What did we agree to? These details can have a huge effect on many industries.
- The decisions of departments under the control of the Executive Branch like the EPA, FDA, or FAA
- The President’s own decisions, for example, if the President knows they will institute tarrifs. (Though there is a lot of overlap with manipulation here)
Is there any mechanism to prevent this? No, aside from public outrage and the democratic process.
Until the current administration, every president in the modern era has voluntarily put their assets into a blind trust to prevent corruption (including insider trading) or the appearance of corruption. In a blind trust, one’s assets are being actively managed, but the owner is not aware of how they are invested and cannot control or influence their management. In this situation, insider trading is impossible since the President cannot actively manage their investments.
This policy is not a law or rule, though, it was just a tradition; and there’s nothing stopping a president from refusing to do so (as President Trump has), in which case insider trading would be easy to carry out. NOTE: I am not aware of any evidence that Trump has engaged in insider trading or stock market manipulation, but it would be trivially easy for him to do so.
So, what mechanisms can prevent this? It’s unlikely that the SEC could bring charges, even if they wanted to, as the President is likely protected by executive privilege. Pretty much the only options would be Impeachment or being voted out of office by a public outraged by a President who used their office to enrich themselves. As @Accumulation pointed out, the STOCK Act makes insider trading by politicians and government employees illegal, but without an enforcement mechanism that applies to the President, the only remedy remains Impeachment or getting voted out.