Order expiry and write-offs
Follower mirrors are marketable-limit orders — a limit priced through the leader's fill, so slippage is capped. The cap has a cost: in a fast or thin market, a mirror can rest unfilled. Order expiry decides how long you are willing to wait.
The setting
On Risk Management, the Order expiry card has one field: Seconds. After that many seconds, an unfilled follower order is cancelled. Blank or 0 means wait forever; the maximum is 86400 (one day). Click Save and the change applies immediately — even while the copier is running. The toast confirms which mode you are in: "Follower orders will be cancelled after Ns if they have not filled." or "Order expiry is off — follower orders wait for as long as it takes."
What a write-off is
When an order expires, the quantity it missed is written off. The engine records "this follower is running N contracts light on this instrument" and moves on. It deliberately does not re-send the order at market.
That is the whole design. An expiry only triggers when the market has moved away from your fill price. Chasing at that moment buys the fill at the worst available price at exactly the moment the market ran from you — the trade you would least want, filled at its most expensive. If the follower missed the entry, MirrorFill accepts the miss: the follower simply runs that much smaller for the rest of the position.
When a write-off clears
A write-off is scoped to the position it was about and ends with it:
- The leader goes flat or reverses. The old episode is over; the next position copies at full size.
- You press Flatten all and then Resume. A deliberate restart clears every write-off — the engine re-chases everything from a clean slate.
- The follower stops copying (its rule is paused or a risk lock takes it out). The debt is dropped so it cannot silently under-size the account when it comes back.
A write-off can never outlive the position it belonged to, and it never grows into a market order behind your back.
Quick answers
Why not just re-send the order at market?
Because the market has, by definition, moved away — that fill would be at the worst price available at the worst moment. A capped, visible miss beats an uncapped, automatic bad fill.
What happens to the exit if the entry was written off?
Targets shrink by the written-off amount, toward flat and never past it. A follower that entered 2 lots instead of 3 exits 2 lots — it is never asked to sell contracts it does not hold.
Do I need to restart the copier after changing the setting?
No. Saving the Seconds field applies immediately, even mid-session.