Broker-side stop adjustments at the open

[Fairman]

Broker-side stop adjustments at the open

A stop order placed over the weekend sits on the server. On Sunday evening, the first quotes arrive, possibly with a gap. Some brokers adjust the trigger and fill rules for orders in that first minute.

The rule might be a delay, with no stops processed for the first thirty seconds, or a wider tolerance, allowing the fill to be worse than usual. It protects the broker from a bad first print, and its effect on the client is a worse fill.

Documentation exists in some execution policies, in a section about "market opening". It's rarely read.

The sign in a log is a stop filled several seconds after the first tick that would have triggered it, at a price well beyond the stop level.

A scalper rarely holds positions over the weekend, but pending orders are another matter. A stop entry placed for Monday may trigger on the gap, at a price that's the worst of the day.

Cancelling pending orders on Friday and re-placing them after the market has settled on Sunday or Monday avoids the gap entry.

One way to find out what a broker actually does at the open is a controlled test. Place a far pending stop on a liquid pair on Friday at a level that Sunday's gap is unlikely to reach, leave it, and then watch how the broker's feed treats it on Monday. That says little about a gap fill. A better test uses a very small position with a stop inside a typical Sunday gap range, and then compares the fill with the first prints in tick history.

The result won't be conclusive from one try, but a pattern across several weekends can reveal whether stops get a delay or a wider tolerance.

Is a special rule for the first minute of the week written in the execution policy of the broker used here?

[FXS Prop Desk]

The rule might be a delay, with no stops processed for the first thirty seconds, or a wider tolerance, allowing the fill to be worse than usual.

A thirty-second delay on stops at the Sunday open means a weekend stop can fill well beyond its level. Reading the broker's execution policy for "market open" rules, and avoiding weekend positions with stops close to Friday's close, are the two practical defences.

[Amanhasnoname]

I learned about this the expensive way with a buy stop on GBPJPY that I forgot to cancel one Friday. Sunday opened with a gap of roughly forty pips through my level, and the fill came in nearly twelve pips beyond the first print I could see in the tick history. When I asked support, they pointed me to a short paragraph about "illiquid opening conditions" that I had never read.

After that I ran something close to your controlled test over about six weekends, using the minimum lot size and a stop placed inside the usual Sunday range. Five of the six fills arrived between ten and twenty seconds after the first qualifying tick, which told me there was a processing delay rather than simple bad luck.

My routine now is boring but effective. Every pending order gets deleted before the Friday close, and nothing goes back on until the spread has settled to normal on Monday, usually well into the Tokyo session.