Ghost orders that survive rollover

[Fairman]

Ghost orders that survive rollover

Pending orders have an expiry setting. Good till cancelled means the order stays until filled or removed. A forgotten order can sit for days.

The danger is that it fills at a random time, in conditions entirely different from those that prompted it. A buy limit placed on Monday's setup fills during Thursday's news spike, with no relation to the original idea.

Brokers handle the rollover for pending orders differently. Some keep them. Some cancel them. Some adjust the price for swap on certain instruments.

A short audit of open pending orders at the end of each session prevents surprises. Another approach is to set an expiry time on every order, even if the strategy does not need one.

Scalping strategies rarely need orders to last overnight. A rule of cancelling everything at the end of the session is cheap insurance.

Has a forgotten pending order ever filled at an odd time and created an unplanned position?