A simulated fill at FPT is determined from two things: the live market price at the moment the order is processed, and the available liquidity in that market near that price. Both are checked before the order fills.
FPT does not fill at stale prices. If the price has moved too far between the moment you saw an estimate and the moment the order is processed, the system requotes or rejects the order rather than filling you at a price the market has already left behind.
The Sequence an Order Goes Through
- You build the order. The order interface shows your account max open size, the market-specific maximum position, an estimated fill price, and estimated slippage or price impact.
- Size is validated. The order is checked against your allowed position size — the lower of your account max open size or 5% of that market's trailing 24-hour volume. Over the limit, it is blocked, not trimmed. See Max Open Size and Market-Volume Limits.
- Timing is validated. A market inside its late-entry restriction window before expiration, or already in resolution, will not accept a new position. See Market Expiration and Late-Entry Restrictions.
- Live price and liquidity are checked. The order is priced against the market as it is at that moment, not as it was when the estimate was generated.
- The order fills, requotes or is rejected. If price and liquidity still support the order, it fills and becomes a simulated position. If the price has moved beyond tolerance, the system requotes or rejects.
The Two Inputs That Decide Your Price
Live market price. The current price is the anchor. This is the rule that rules out the most common complaint about simulated environments: you cannot be filled at a price that no longer exists, and you cannot benefit from lag between what the screen shows and what the market is doing.
Available liquidity. Price alone does not determine a fill. How much size is available near that price determines whether your order clears at the top of the book or has to reach further into it. A larger order in a thinner market reaches further, and the estimated fill reflects that.
Estimates Are Estimates
The estimated fill price, estimated slippage and estimated price impact shown on the order interface are estimates and are not guaranteed. They are FPT's best modelled expectation given the market at the moment you looked at it.
Your realised simulated fill can differ from the estimate whenever the market changes between the estimate and the processing of your order — which, in an active prediction market, is normal rather than exceptional. The full treatment of that is in Estimated Slippage and Price Impact.
FPT does not promise a fill price, does not guarantee a fill at the estimate, and does not treat a difference between the estimate and the realised fill as an error in itself.
Why an Order Might Not Fill
| Reason | What you see | What to do |
|---|---|---|
| Order exceeds allowed position size | Blocked, with the market's 24-hour volume and your maximum position stated | Resize to the stated maximum |
| Market inside its late-entry window | Blocked as restricted | Choose a market with more time to expiration |
| Market in resolution or dispute | Not tradeable | Wait for FPT to restore it, if it is restored |
| Price moved beyond tolerance | Requote or rejection | Review the new price and resubmit if you still want it |
| Market temporarily restricted | Not tradeable | See the dashboard notice for the restriction |
| Liquidity insufficient at any acceptable price | Rejection | Reduce size or choose a deeper market |
Restrictions are covered in Temporary Market Restrictions and thin-market behaviour in Market Availability and Thin Markets.
Requote or Reject, Never Stale
When price moves too far before an order is processed, FPT has two honest options and takes one of them:
- Requote. The system comes back with the current price so you can accept the market as it actually is.
- Reject. The order does not fill.
What it does not do is fill you at the old price. That would be a gift in one direction and a theft in the other, and either way it would make the evaluation meaningless as a measure of trading skill.
Fills and Your Rules
A fill is the moment a position starts counting against every account rule at once:
- It counts toward your max open size for that market.
- Its profit and loss moves your end-of-day trailing drawdown floor, which trails upward with profit and locks $100 above your starting balance — $25,100, $50,100 or $100,100.
- Its profit and loss counts toward your maximum loss — $1,000, $2,000 or $3,000 by account size — with no daily loss limit in between.
- The day it lands on counts toward the 40% consistency rule and toward your profitable days.
The parameters are set out in Complete Evaluation Rules by Account Size.
A Simulated Fill Is Not a Real One
Your simulated order never consumes real liquidity at Polymarket or Kalshi, never appears on a real order book, and never moves a real market. FPT does not route customer orders to any venue.
That means a simulated fill is a good-faith reconstruction of what a fill would plausibly have looked like given the market data — not a record of a transaction that occurred. Simulated performance is not a prediction of live performance. The formal statement is in the Simulation and Risk Disclosure.
Still Need Help?
If a fill looks wrong rather than merely unfavourable, email support@fundedpredictiontrader.com with the market, the order, the timestamp and the estimate you were shown, and the support team can review the record.