Sorry Trump is not worth $9 Billion. Where did you get that figure, that is what Trump tells everyone but it’s not true.
All through his career Trump has bragged about his net worth and it always turns out he’s lying. I checked Forbes and they peg him at about $4 Billion.
Most of Trump’s wealth are in real estate and not liquid assets such as Bonds or Treasury Notes, and Cash.
So he either sells assets or he borrows against them.
It is what his accountants filed with the FEC so take it up with them.