> Where did that money come from?

The value created by his company. That value can be turned into money by selling shares of it (stocks), or by borrowing against it (bonds).

Money is created by banks. When banks loan you money, that money is created by a notation in the bank's ledger. But they only loan money on collateral, which would be in this case the value of the company. The money gets destroyed (!) when the loan is paid off. But the value of the collateral remains.