$ In the "operate case" you liquidate the portfolio at $t_1$ realising its PnL (allow me to simplify the notation a little) In the meantime it's the conclusion in the working day and time for Trader B to hedge, but he has nothing at all to delta-hedge as the stock https://angelosiuha.vidublog.com/33107141/5-simple-statements-about-pnl-explained