"why was he paid over ONE BILLION by a subsidiary of the Bank of China"
That deal was nearly 6 years ago. Their fund was already worth some $2.4B by then.
A bit of quick Googling should help answer your questions. (Hint - don't just look at Schwizer's book).
When you arrive at the numerous Gateway Pundit articles, you will find this gloriously ironic comment.
"On Sunday former Trump strategist Steve Bannon called on Joe Biden to release his tax returns to prove he is not compromised by the Communist Chinese government".
