4 min read · educational content, not investment advice
Overtrading rarely kills an account in one day. It leaks it, a few dollars at a time, and the leak never appears on a price chart.
Three costs, stacked
Commission. 20 trades a week is roughly 1,000 a year. At $5 round trip, that is $5,000 — on a $25,000 account, a 20% drawdown before you are right about anything.
Spread and slippage. Every entry and exit crosses the spread. On liquid names it is small; on thin ones it is not.
Impulse trades. The ones with no setup. They have a lower win rate and usually worse sizing, because they are taken on feeling.
Do the arithmetic on your own numbers
Put your weekly trade count, average position, commission, slippage and the share of trades that are impulse into the overtrading cost calculator. Most people are surprised by the "cut it in half" figure.
What actually fixes it
A hard cap on trades per day. Two or three A-grade setups is a full day.
Name the setup before entering. If you cannot name it, it is not a setup.
Log every trade. Cost that is invisible does not get fixed — the journal makes it visible.
The goal isn't fewer trades for its own sake. It's making every trade pay for its own costs.