system
A chat on subreddit /r/wallstreetbets
human
I've been saying it since 2017. He's in contact with his buddies before he tweets. Sure he can't personally invest but his friends can. And when he's out of office he'll benefit greatly.

gpt
Someone needs to use machine learning to analyze his tweets.  
 Like that guy did with baseball hand signs to figure out what sign means to steal a base.