Different fill price than the leader
Why a follower fills at a different price than the leader, why market orders slip more than limits, and when a price gap is worth investigating.
Updated
A follower filled a tick or two away from your leader, or two followers filled at slightly different prices? That is slippage, and it is normal market behaviour. Here is why it happens and when to expect more of it.
Why fill prices differ
OmenSyncer sends every follower the correct order almost instantly, but it doesn't set the price you fill at. Your broker does. Between the order being sent and the order filling, the market keeps moving, and each account is a separate order on the broker's side. So two accounts on the same trade can land a tick or two apart, and none has to match the leader exactly.
Each follower fills independently. There is no shared fill price handed down from the leader: every account gets whatever the market offers it the instant its order reaches the broker.
Market orders take the best available price
In the default copy mode, followers enter as market orders. A market order's job is to fill right now at the best price on offer. It always gets you in and out, but the exact price depends on what is available that instant. In a fast or thin market, best available can be a little worse than where the leader got in. That gap is the slippage.
Why Market mode slips more than Limit
Your Execution Mode setting trades certainty against price:
| Mode | How it fills | Slippage |
|---|---|---|
| Market | Follower enters at the best available price the instant the order lands. | Some, but always fills. |
| Limit | Follower mirrors the leader’s pending order at its exact price. | None at that price, but may not fill if the price isn’t reached. |
Market mode accepts a little slippage as the cost of always getting in. Limit mode holds out for an exact price, so there is no slippage on a fill, but a follower can miss the trade if its price never trades. Neither is more accurate; they are different priorities. For how to choose, see Market vs Limit execution.
When a price gap is worth a look
A tick or two, or a bit more in a fast market, is expected. Worth investigating instead:
- A consistently large gap on one account only, which can point to a thin or illiquid contract on that broker.
- A follower that never fills in Limit mode, which usually means its price genuinely isn't being reached, not a copier problem.
The fill price, and any slippage, sit on the broker's side of the line. For the full picture of what OmenSyncer controls versus what your broker controls, see What OmenSyncer controls vs your broker.