How to set a stop loss properly. And never move it against you.

A stop loss is the price at which, if hit, the trade thesis is wrong and you exit. That sentence sounds simple. In practice, almost every retail trader breaks at least one of the rules around stops. They place mental stops instead of hard stops, they move stops away from entry to give losers more room, or they set stops based on dollar amount instead of chart structure. Each break has the same cost: a small loss that became a big loss because the stop was not honest.

This post is the four valid stop methods, the one rule that keeps them honest, and what to do when the stop hits.

The four methods

One. Structural stop.

The stop is placed at a chart level where, if reached, the technical reason for the trade is invalidated. For a long entry on a breakout, the stop sits below the breakout candle or below the prior swing low. For a long entry on a pullback, the stop sits below the pullback low. The stop is set by the chart, not the dollar amount. The position size adjusts to keep the dollar risk at your planned number.

Two. ATR stop.

ATR is the Average True Range, a measure of how much a stock typically moves per day. A common ATR stop is one or one and a half multiples of the daily ATR away from entry. For a stock with $2 ATR, the stop sits $2 or $3 away. The ATR approach gives a stop that is sized to the actual volatility of the instrument, which prevents the common error of setting stops too tight on volatile names.

Three. Time stop.

The trade is closed at a specific time if the planned move has not happened. A swing trade that has not run by Friday close gets exited, regardless of where price is. A day trade that has not run by 11 AM gets exited. The time stop is a forgotten tool. It prevents the slow bleed of trades that are not going anywhere from tying up capital that could be deployed in setups that are working.

Four. Premium stop (options only).

For options, the stop is a percentage of premium paid. Most traders use thirty to fifty percent of premium as the maximum allowed loss on a long option. A $200 contract with a thirty percent stop gets exited at $140 premium. The stop is in premium, not in underlying price, because options carry theta decay and the underlying price stop can hit while premium is still bleeding.

The one rule that keeps stops honest

Tighter is fine. Looser is never.

Once a stop is set, it can be moved in one direction: toward your entry. To lock in profit, to reduce risk after a partial move in your favor, to tighten as the trade matures. It cannot be moved away from entry. Giving the trade "more room" is the most common path from small loss to big loss in retail trading.

The mechanism is psychological. Once you have moved a stop away from entry, you have admitted that the original stop level was wrong. Now you have a trade with no clear invalidation point, because if the new stop hits and you move it again, you have shown yourself that the stop can keep moving. Stops that can keep moving are not stops. They are wishes.

Hard stop versus mental stop

A hard stop is a working order placed with your broker that executes automatically when price hits the level. A mental stop is a number you intend to honor, with the actual exit requiring you to click manually.

Hard stops, every time. Mental stops fail in two ways. One, you hesitate at the moment of exit and the trade has already gone past the level. Two, you decide in the moment that the stop was "too tight" and give it more room. Both failures end the same way: the stop you intended to honor at price X gets executed at price Y, where Y is materially worse.

The hard stop removes the decision from the moment. Set the order when calm. Let the order execute when the level is reached. The trader's job after entry is to monitor, not to renegotiate the trade with themselves.

What about volatile or low liquidity tickers

For ultra volatile names or low liquidity tickers, hard stops can fill at unfavorable prices due to slippage. Two options. One, use a stop limit instead of a stop market, which prevents fills outside a price band but risks the stop not filling at all if price gaps through. Two, trade smaller size, which makes the slippage absorbable.

For most retail trading on liquid major tickers (SPY, QQQ, most large caps, most index options), standard stop market orders are fine. Slippage on those is minor.

When the stop hits

The trade is closed. The loss is what your plan said it would be. The next move is the post loss timeout. Thirty to sixty minutes off the platform. No checking the chart. No looking at "what if I had held." The stop did its job, which was to keep the loss the size you planned. Anything you do in the next thirty minutes that is not waiting is a violation of a different rule.

After the timeout, the next entry runs through the checklist from scratch. The previous trade is closed. It is not part of the next trade's decision.

The trailing stop, briefly

A trailing stop adjusts toward your entry as price moves in your favor. If the stop is set $2 below price and price rises by $1, the stop rises with it. The stop never moves down. The mechanism locks in profit if the trade reverses, while leaving room to ride a winner.

Trailing stops work well on trending trades and poorly on choppy trades. The trade off is that a tight trailing stop will get tagged out by normal noise on a trade that ultimately would have run further. The looser trailing stop avoids the tagouts but gives back more on reversals. Pick the variant that fits your strategy, written into your plan.

Where the audit fits

The audit names your stop method, the rule that keeps it honest, and your specific stop placement language tailored to your setup. Five to seven pages with the stop rule on paper where you can read it before every trade.