If you borrow against it you still have to pay interest. If he somehow found someone to loan him $1T, which would probably be practically impossible, the interest would make the total amount he got less than $1T.
if you borrow against it and buy shares of stock, the stockmarket generally can be counted on for at least 7% returns, and the borrowing cost would be 5%, so no, chances are the interest would not eat up the borrowing.