A trailing stop is a stop-loss that follows the price as a trade moves in your favor and never moves back. On a long position it rises a set distance below each new high, measured in dollars, percent or a multiple of the average true range (ATR), so a winning trade can keep running while part of the open gain is protected.
How it works
Every trailing stop has two parts: a reference price and a distance. For a long trade the reference is the highest price since entry, often called the high-water mark, and the stop sits the chosen distance below it. When the stock makes a new high, the stop moves up with it; when the stock falls, the stop stays where it is. Once the price reaches the stop, the position is sold. A short trade works the other way round, with the stop trailing above the lowest low.
There are two practical ways to run one:
- A trailing stop order at the broker. You enter the distance in dollars or percent, and the broker recalculates the stop price as the market moves. When triggered, it becomes a market order. A trailing stop-limit order instead sends a limit order at a set offset from the stop, which controls the price but may not fill; the difference is explained in stop vs stop-limit orders. Brokers differ on which price updates the high-water mark (the last trade or the bid), whether the order works outside regular trading hours, and whether they offer it at all, so check the broker's order rules before relying on one.
- A chart-based trail updated by hand. After each close, an ordinary stop order is moved to a level defined by a rule: below the lowest low of the last n sessions, below a moving average, below the latest swing low, or a multiple of ATR under the highest high. The last one is the chandelier exit, described in ATR stop. The stop moves once a day, in steps, and follows the trend's structure rather than the last print.
How to set the distance
The distance is a trade-off. A tight trail exits soon after the trend pauses and keeps more of a short move, but ordinary pullbacks stop it out early. A wide trail survives pullbacks and can hold a long trend, but gives back more when the trend finally ends. Three guidelines help:
- Scale it to volatility. A flat 5% is wide for a quiet utility stock and tight for a stock that moves 4% on an average day. An ATR multiple, or a percentage checked against ATR, adapts to the stock.
- Match the holding period. A 10-day low suits trades held for a few weeks; a 50-day moving average suits trends held for months.
- Decide when trailing starts. Many traders keep the initial stop, placed where the setup fails (see stop-loss placement), until the trade has gained about 1R, and begin to trail only then. A trail that starts on the entry day is often hit by the first normal pullback.
Worked example (illustrative numbers)
A stock is bought at $50.00 with an initial stop at $46.00, a risk of $4.00 per share (1R). Two exits are compared: a 10% trailing stop order entered with the trade, and a chart-based trail under the lowest low of the last 10 sessions, which takes over from the initial stop once that low rises above $46.00.
| Stage | Price | 10% trailing stop order | 10-day-low trail |
|---|---|---|---|
| Entry | $50.00 | $45.00 (the $46.00 initial stop stays active) | $46.00 (initial stop) |
| First high | $56.00 | $50.40 | $51.20 |
| Pullback | $53.50 | $50.40 (unchanged) | $51.20 (unchanged) |
| Highest high | $62.00 | $55.80 | $57.30 |
| Trend turns | falls through both | sold near $55.80: +$5.80, +1.45R | sold near $57.30: +$7.30, about +1.8R |
At the high, the open gain was $12.00 per share, or 3R. The percentage trail gives back $6.20 of it and the 10-day-low trail $4.70. Neither exit sells at the top: the giveback is the price of staying in the trade until the trend shows it has ended. Had the stock instead gapped down overnight from $60.00 to an open of $54.00, both stops would have filled near $54.00, below their stop prices.
Limitations and common mistakes
- Trailing too tight. A stop inside the stock's normal daily range turns noise into exits and cuts off the large winners that trend methods depend on.
- Gaps. A trailing stop is still a stop: an overnight gap fills at the next available price, often below the stop, and a trailing stop-limit may not fill at all.
- Intraday spikes. A broker order can trigger on a brief drop even if the stock closes higher; a trail checked only on the close avoids that but reacts a session later.
- Loosening the trail after a pullback, which defeats the rule. A trailing stop moves in one direction only.
- Treating breakeven as safe. Moving the stop to the entry price early removes the planned loss, not the risk of a gap, and raises the chance of a scratch exit on normal noise.
- Judging the exit by one trade. Compare trailing rules over many trades in a backtest.
In Clear Tape
Two preset systems use a trailing stop: the Leader Trend Filter and the 52-Week High Breakout trail at the 22-day high − 3 × ATR(22), a chandelier stop that only moves up. In trading systems the trail is drawn on the chart; in backtests each session's stop is the tighter of the initial stop and the trail, checked against the day's low, and a session that opens below the stop exits at the open. Backtests are available to Tools and Pro members. In the free trade journal, R is measured from the initial stop, and MFE, the best price reached while the trade was open (from daily bars), shows how much of the open gain a trailed exit gave back.
For educational purposes only. Not investment advice.