$ Within the "work situation" you liquidate the portfolio at $t_1$ realising its PnL (allow me to simplify the notation a bit) To make the two approaches equivalent you should imagine investing/borrowing $PnL_1$ at price $r$ to make sure that it stays in the method until eventually $t_2,.$ At the https://pnl93467.educationalimpactblog.com/55772304/pnl-options