You repay the loan with the next loan because you have $10b in stock but only took out a $10m loan. In the meantime the stock appreciates some more or you have

You repay the loan with the next loan because you have $10b in stock but only took out a $10m loan. In the meantime the stock appreciates some more or you have more vested stock. I guess the risk here would be that the stock goes to 0, you get margin called AND you are now on the hook to pay taxes.