Something I only recently started paying attention to is how misleading the P&L on a multi leg position can get during a fast move.
I had a QQQ debit spread open while trading the same directional move on Moon. The underlying trade was behaving pretty much how I expected, but my options position was showing a way bigger gain than made sense.
When I actually looked at the combo market, there was no realistic fill anywhere near the mark my broker was using. The bid ask on both legs had widened and the midpoint was basically creating a profit that didn't exist yet.
Since then I've started recording the executable bid on the entire spread when reviewing trades, not whatever P&L number the platform shows me.
Its changed a few trades I originally journaled as good exits too. On paper I "gave back" a bunch of profit, but at the time there was never actually a buyer at the earlier marked price.