Trailing stops

Trailing is opt-in per trade via the manual form's Exit Mode selector (with a Trail Multiplier field) or a webhook trail=N value (requires EA v1.6.0+). The multiplier sets when the trail activates: trail=1 activates after price moves 1× the SL distance into profit, trail=2 after 2×, trail=1.35 after 1.35×. Once active, the SL trails behind price by exactly 1× the SL distance regardless of the multiplier; only the activation trigger scales.

The trail only ratchets in your favour. It never widens the SL. A trade cannot use both a fixed TP and trailing stop; selecting trailing sends TP as 0 for that trade.

The multiplier changes when, not how far

This is the part that surprises people. trail=3 does not trail three times wider. It waits three times longer to start, then trails at exactly the same distance as trail=1.

SL distance = 20 pips, trail = 3

price moves +59 pips  → nothing happens, trail is still dormant
price moves +60 pips  → trail activates, SL jumps to 40 pips of profit
price moves +75 pips  → SL follows to 55 pips of profit
price falls back      → SL stays at 55 pips of profit

A higher multiplier gives the trade more room to breathe before the stop starts moving. It does not change how tightly the stop follows once it does.

What the trail measures from

The activation distance is the stop-loss distance multiplied by N, measured from the position's actual open price as your broker recorded it, not the price in your alert. Slippage on entry therefore shifts the activation point with the fill.

Progress is measured against the side of the spread you would exit on: the bid for a long, the ask for a short. A long is judged by what you could sell at, which is the honest measure of whether the trade is actually in profit.

Where the trailing distance comes from

The EA needs a stop distance to trail by, and it takes it from the trade's own stop loss. In price mode that is the gap between the fill and the stop; in pips mode it is the pip distance converted at the symbol's tick size.

A trade with no stop loss gets no trailing stop. There is nothing to derive the distance from, so the trail is never registered. If you send trail=2 with no sl, the trade opens unprotected and stays that way.

The stop never moves against you

Once active, a new stop is only accepted if it is better than the current one, by at least one point. A retracement leaves the stop where it is. The stop ratchets and never gives ground.

The one asymmetry: if a position somehow has no stop at all, the first trailing update sets one unconditionally, because there is no existing level to improve on.

After an EA restart

Trailing registrations survive a restart. The EA stores each position's trailing distance and multiplier in MT5 global variables and restores them when it starts, and it can also recover them from the position's comment if the stored entry is gone.

One cosmetic consequence: the activated flag is not restored, so a trail that had already engaged logs "Trailing stop ACTIVATED" a second time after a reload. The stop itself is unaffected, since it can only improve.

Two limits worth knowing

Trailing is evaluated on the chart's own ticks. The EA runs on one chart, and the trailing loop runs when that chart's symbol ticks. If you attach it to a quiet symbol and trade a busy one, updates are less frequent than the traded symbol's price action.

Broker minimum stop distance is not pre-checked. If your broker refuses a stop for being too close to price, the modification is rejected and logged rather than retried at a legal distance. On symbols with a wide stops level, a very tight SL distance can mean the trail logs rejections instead of moving.