[Feature request] Total profit/loss for position

I miss total PnL (profit and loss) on each position.
Lets say I buy $100 of XYZ, then panic sell for $50. My loss is $50.
Then I buy again $100 of XYZ, it goes to $120, but my Investment gain/loss shows only $20 of profit.
Can we add another calculation which would show Total Investment gain/loss, in this example it would be $30 loss.