SEC Chair
As I understand it, by law Trump cannot replace the SEC chair for a few more years. When that happens, the net effect will probably still be small since most of that job is determined by Congress.
Congress is almost completely red. So of course they are going to do whatever Trump wants them to do and pump whatever laws and regulations (or lack thereof) that he wants in place. Includes replacing SEC head if they find some ancient provision that lets them get away with it.