Stop loss vs profit lock: what is the difference?

Key takeaways

• A stop loss answers “how much can I lose from here?”; a profit lock answers “how much of this gain will I give back?”
• The two are the same tool framed for different stages of a trade.
• Both should be anchored to volatility and current price, not your entry or a round number.
• Neither removes uncertainty, a news gap can jump straight through any level.

Two questions, one mechanism

A stop loss and a profit lock are both just a pre-decided exit level. What separates them is the question each is answering. A stop loss is downside-first: placed near entry to cap the loss if the trade is simply wrong. A profit lock is gain-first: placed once the position has moved in your favour, to protect the profit you are now sitting on. Knowing which question you are answering tells you where the level belongs.

Stop losses: protecting capital from entry

When you first open a position, the risk is that your thesis is wrong and the stock falls from where you bought. A stop loss caps that. The key discipline is sizing the position so that being stopped out costs only what you decided to risk, the stop distance and your risk budget together set how many shares you can hold.

Profit locks: protecting a gain you already have

Once a stock has run in your favour, the question changes. You are no longer protecting your entry, you are protecting an unrealised gain. A profit lock is therefore anchored to the current price, not the price you paid, and it typically trails upward as the stock makes new highs so more of the gain is banked over time.

Why fixed-percentage stops fail both jobs

A flat “I’ll sell if it drops 8%” ignores the stock entirely. On a calm name it may sit miles away and protect almost nothing; on a volatile one it triggers on routine noise and shakes you out before the move plays out. Both a sound stop loss and a sound profit lock need to reflect the stock’s actual volatility, which is why a single percentage rarely serves either well.

Both still need judgment

Neither approach removes uncertainty. The right level depends on volatility, trend, position size, liquidity, and your own constraints, and an overnight gap on news can move straight through any pre-set level. Treat both as disciplined estimates that make your decision more consistent, not as guarantees.

Common questions

Can I use both at once?

Yes, they are stages of the same trade. Many investors open with a stop loss to cap initial risk, then, once the position is comfortably in profit, manage it as a profit lock that trails upward to protect the gain.

Does a profit lock have to be a trailing stop?

Not necessarily, but trailing is the natural fit. A fixed profit-lock level still protects a gain, but a trailing version banks more of the upside as the stock climbs and only ratchets in one direction.

Which does PnLock’s Profit Lock do?

Profit Lock is gain-first and anchored to the current price. It computes several exit models, including a Chandelier-style trailing exit, and grades them, so you can compare a tight protective level against a roomier trailing one before deciding.