Known limitations
Every tool has edges. Here are ours — and where a limit is a design decision, we say why. If something on this page is a dealbreaker for you, better to know now.
Execution
Unfilled quantity is written off, never chased. With order expiry on, a follower order that hasn't filled after your N seconds is cancelled and the missed quantity is written off. We deliberately never re-send it at market: by the time an order has sat unfilled through your expiry window, the price has moved, and chasing it converts a missed fill into a bad one. The written-off amount clears when the leader goes flat or reverses.
No synthetic stop or target brackets. Followers mirror the leader's own exits, delta-exact — when your stop or target fills on the leader, every follower closes with it. MirrorFill does not attach brackets of its own on top. Two bracket systems working the same position can disagree, and a copier that quietly manages exits you didn't place is a copier you can't reason about. How this plays out in practice: how exits copy.
Platform coverage
Futures only. MirrorFill runs on a fixed registry of CME, CBOT, NYMEX, and COMEX instruments with known tick sizes. No equities, no spot FX.
Supported platforms are Rithmic, Tradovate, and Volumetrica (dxFeed). There is no NinjaTrader, TradingView, or MetaTrader 4/5 support. Topstep's TopstepX / ProjectX platform is not supported — if your accounts live there, MirrorFill can't copy them today, and we'd rather say so plainly than let you find out after signing up.
One Tradovate session per login. Tradovate allows a single active session per login, so running the copier and another tool on the same credentials can conflict. If your followers are on Tradovate, see Tradovate session conflicts.
While the copier runs
Copy rules are read-only while the engine is running. Structural changes — adding a follower, changing the leader, changing sizing — require a stop first. This is deliberate: the engine's routing is fixed while live, so an edit can never land halfway through a fill. The per-follower Follow switches still work mid-session, so pausing one account never requires a stop. Details: editing rules while the copier runs.
Alerts and billing
No e-mail alerts for engine events yet. Disconnects, copy failures, and risk hits raise in-app alerts today (the bell in the topbar). Per-event e-mail is on the roadmap — the toggles are visible in Settings but disabled until it ships. The Weekly Review e-mail does work today.
Monthly billing only. There is no annual plan. Plans are on the pricing page.
Speed
We publish no latency number. We haven't measured copy latency under production load, so quoting one would be a guess dressed as a benchmark. What we can say: copying is triggered by fills and happens in real time, as fills happen. If we publish a figure one day, it will come with the methodology.
Quick answers
Will you add NinjaTrader or TradingView?
Not today, and we don't announce dates. If your accounts run on Rithmic, Tradovate, or Volumetrica, they connect like any other account on that platform.
Can I turn off the write-off and chase missed fills at market?
No. Never chasing at market is a deliberate engine rule, not a setting.
Is there an annual plan?
No — monthly only, on three tiers. See pricing.