Almost no account blows up because of one bad trade. It blows up because of what the trader does after that bad trade. That behaviour is called revenge trading, and it's one of the biggest account destroyers out there. The good news: you can see it coming and you can cut it off. Let's get to it.
Revenge trading is going back into the market driven by the anger of having lost, not by a good signal from the market. You've just taken a loss, you feel robbed, and you want that money back now. So you jump in again, faster, with more size, with no plan. You're not trading the market: you're trading against your own frustration.
The name says it all: you're after revenge. But the market doesn't know you exist, and it owes you nothing. The one you really take revenge on is your own account.
It always follows the same staircase. Recognising it is half the battle:
Notice that the problem isn't the first loss. It's the jump from "anger" to "trade more". That's where you lose control, and that's where you have to hit the brake.
When you're calm, you respect your stop, your size and your ratio (if that sounds like gibberish, check out risk/reward ratio). When you're angry, your brain switches modes: it wants immediate results and stops calculating risk.
That's why the revenge trade usually carries double or triple your normal size, with no stop or with the stop miles away, at an awful moment in the market. It's literally the worst trade you'll make all day... and you make it with more money than any other. That combination is what turns a small loss into a disaster. It's not bad luck: it's chemistry. Anger shuts down the part of your brain that manages risk.
Willpower isn't enough: in the heat of the moment it always loses. What works are rules decided when calm that act for you. These are the basics:
The simplest and most powerful rule is to step away from the screen. After a loss that has shaken you, get up. A glass of water, a walk, five minutes of breathing. It sounds trivial, but you give the anger time to drop and your rational brain time to come back.
Set a concrete cooldown time: "after a heavy loss, 15 minutes away before I even think about another trade". And if the day has been truly bad, the best trade is not to trade. Closing on a small, controlled red is winning; closing on a huge red out of stubbornness is losing in the worst way.
Here's the honest bit: we all believe we'll stop in time, and hardly anyone does in the heat of it. That's why it makes so much sense to lean on something external that enforces your rules even when you, in that moment, don't want it to. A daily limit that cuts you off by itself, an alert when you're several losses deep, a brake that won't negotiate with you. Discipline costs less when it doesn't depend on your mood. And if you also work on your head in parallel, even better: take a look at trading psychology.