Every trader can list their mistakes. Few know what each one costs. Mistake cost answers that: tag every trade on which you broke a rule with what you did (FOMO entry, moved stop, oversized, revenge trade), then add up the results of the tagged trades.
How it is computed
mistake cost = Σ net P&L of trades with at least one mistake tag
per tag: count, Σ net P&L, average, win rate
A trade with two tags counts once in the total and once under each of its tags.
Example
A month of 60 trades:
The month made $1,520. Without the nine tagged trades it would have made $3,450, more than twice as much. The moved stops cost the most with only two trades, which tells you where to start.
Reading it honestly
- The cost is what the tagged trades actually returned, not a guess at what a clean version would have done. A tagged trade can win; it still counts.
- Tag winners too. A winning revenge trade teaches the habit that will cost you later.
- Watch the clean row as well: it is your strategy's real performance when you follow it.
In SetupBook
Ten mistake tags are built in (FOMO entry, early exit, no stop, moved stop, revenge trade, oversized, late entry, unplanned entry, overtrading, pre-news trade) and you can add your own. The dashboard shows the total mistake cost and the discipline rate as cards, with the most expensive tags listed under them; Analytics compares every tag with the trades that have no mistake.