Your safety net: the stop-loss

A stop-loss is an order that sells automatically if the price falls to a level you chose. It turns “I'll see” into a decision taken while you're calm.

Place it where your idea is proven wrong, not at a random round number. And accept that it will sometimes trigger just before the price bounces — that's the price of never losing everything.

A take-profit does the same on the way up: it sells at your target, so greed doesn't decide for you.