$ During the "get the job done scenario" you liquidate the portfolio at $t_1$ realising its PnL (allow me to simplify the notation a tiny bit) Vega and Theta are sensetivities to volatility and time, respectively, so their contribution will be: Now, in the above rationalization, we assumed the inventory https://pnl59124.blogkoo.com/pnl-for-dummies-53485361