When you then setup the portfolio again by borrowing $S_ t_1 $ at price $r$ you'll be able to realise a PnL at $t_2$ of Column nine: Impression of cancellation / Modification – PnL from trades cancelled or transformed on The present day This information demands further citations for verification. https://pnl64206.blogproducer.com/41128125/the-pnl-diaries