Surely the number one suspect for having made this trade, is Trump himself (and/or his immediately family)? Nobody knew better exactly what would be announced and when, than the guy who did the announcing. Ownership could be hidden behind trust / shell structures, possibly indefinitely, or at least until it's too late for anyone to do anything about it (although in Trump's America, I doubt that anyone could do anything about it anyway). We already know that he's unscrupulous and unprincipled. We already know that he's an indicted felon.