The daily loss limit

Risk per trade protects you from one bad trade. A daily loss limit protects you from one bad day. It is the most you will lose in a single session before you stop trading and close the platform.

Most people who day trade lose money, and a lot of the damage happens on a few awful days. Those days rarely start with one huge loss. They start with a normal loss, then a trade to win it back, then another.

Why it exists

After a few losses, your judgment changes. You feel pressure to get back to even, and that pressure leads to trades that are not your setup. People call these revenge trades. They tend to be larger, faster and worse planned than the trades that came before them.

A daily loss limit takes that choice away. You make the decision in the morning, when you are calm, and you follow it in the afternoon, when you are not. It turns a possible disaster day into an ordinary losing day.

How to set one

A simple way is to base it on your risk per trade. Many traders set the limit at two or three losing trades' worth. That is a common rule of thumb, not a research finding, so treat it as a starting point.

Here is an example. Say you risk $50 per trade. A limit of three losing trades is $150. Once you are down $150 for the day, including costs, you are done. It doesn't matter if the next setup looks perfect.

Your limit should fit your setup. If your plan only allows a few signals per session, a limit of two or three losses fits well. If you find you hit the limit often, the answer is usually smaller size, not a bigger limit.

Stopping for the day

A limit only works if stopping is automatic. Decide now what "stop" means. For most traders, it means flatten any open trade, cancel any orders, and close the platform. Then write in your record what happened and walk away.

Some traders also set a rule for the next day. For example, after hitting the daily limit, they trade half size the next session. That is optional, but it gives you a calm restart.

It also helps to cap the day in other ways. You might set a maximum number of trades or a fixed end time. That way a good morning doesn't turn into a long afternoon of extra trades you never planned.

Tools that enforce it

Willpower is not a great safety system. Some trading platforms and brokers let you set a daily loss limit that blocks new orders or flattens your account once you reach it. Check your platform's risk settings and use the feature if it has one. If it doesn't, set an alarm and a written rule.

Prop firm accounts usually have daily loss limits built into their rules, and breaking one can end the account. Each firm sets its own limit and measures it its own way. If you are comparing firms, Prop Firm Duel (my own site) lays out their rules side by side. Even then, set your own personal limit inside the firm's limit, so the firm's rule is never the one that stops you.

The takeaway

A daily loss limit caps how much one bad session can cost you. Set it in advance, often at two or three losing trades' worth, and stop completely when you hit it. Use your platform's tools to enforce it if you can.

Do this today

• Set a daily loss limit in dollars, based on your risk per trade, and write it down.
• Look in your platform's settings for a daily loss limit feature and turn it on.
• Write what you will do, step by step, when you hit the limit.
• Review any day in your record where you lost more than the limit, and note what happened.

Check yourself

Answer each one in your head, then open it to check.