It's not though. He was already invested, Trump attempts to close the de minimis exemptions, Trump walks back closing the exemptions.

If he'd invested just before the walk back occurred that could have been insider trading but he appears to have had this investment for a while. What it demonstrates instead is that Trump's foreign policy is, potentially, beholden to the investments of his staff. Which might be worse. I'd rather someone make a few million on insider trading than have us flip-flop on policy decisions because someone happened to be invested in an impacted company.