A thin market is one with low trailing 24-hour volume. Thin markets are not banned at FPT, but they are heavily size-limited: because no position may exceed 5% of a market's trailing 24-hour volume, a market that has traded $5,000 in the last day allows a maximum position of $250 — no matter whether your account is the $25k or the $100k.
FPT labels a thin market clearly in the dashboard and shows available size on market cards where it can, so you find out before you build an order rather than after.
Why Thin Markets Are Limited
The market-volume cap exists to keep the simulation honest. A simulated position that would represent a large share of a market's entire daily turnover cannot be modelled realistically — in a live market, an order that size would move the price against itself and might not fill at all.
Capping every position at 5% of trailing 24-hour volume keeps simulated fills within a range where estimated price and liquidity mean something. It applies equally to markets from both covered sources; a thin market is a thin market regardless of where its data came from.
What Size a Thin Market Actually Allows
Your allowed position is the lower of your account max open size or 5% of that market's trailing 24-hour volume. In a thin market, the second number is always the binding one.
| Market 24h volume | Maximum position, any account size |
|---|---|
| $1,000 | $50 |
| $2,000 | $100 |
| $5,000 | $250 |
| $10,000 | $500 |
| $15,000 | $750 |
| $20,000 | $1,000 |
Notice that every row above is identical for the $25k, $50k and $100k accounts. Below $20,000 of daily volume, account size is irrelevant — the market is the constraint.
The Volume You Need for Your Full Size
The reverse question is more useful for planning: how much volume does a market need before your account's own limit is the one that binds? Multiply your max open size by 20.
| Your max open size | Volume needed for full size |
|---|---|
| $500 | $10,000 |
| $1,000 | $20,000 |
| $1,500 | $30,000 |
| $2,000 | $40,000 |
| $2,500 | $50,000 |
| $3,000 | $60,000 |
| $3,500 | $70,000 |
A $50k evaluation account carries a $2,000 max open size, so it needs a market with $40,000 of trailing 24-hour volume to deploy that fully. A funded $25k account at funded start carries $500, so $10,000 of volume is enough. The complete rule with per-account tables is in Max Open Size and Market-Volume Limits.
Volume Moves, So Your Limit Moves
Trailing 24-hour volume is a rolling figure. A market can be deep in the morning and thin by evening, particularly around news events, and the maximum position it allows you moves with it.
Two consequences worth planning around:
- The maximum position you see now is not a reservation. If you come back later and volume has fallen, the limit will be lower.
- The limit applied to an order is the one in force at the moment the order is submitted, not the one displayed when you started building it.
Why a Market Might Not Be Available at All
Thinness limits size. Some conditions remove a market from the tradeable set entirely:
- It is outside FPT's covered set. FPT covers selected markets from both sources, not every market that exists. See Polymarket and Kalshi Market Coverage.
- It has expired and is awaiting resolution, or its resolution is disputed or delayed. See Market Resolution and Data Dependencies.
- It is inside its late-entry restriction window before expiration. See Market Expiration and Late-Entry Restrictions.
- Its data feed is degraded, delayed or has stopped updating, so a fill cannot be checked against a reliable live price.
- FPT has restricted it temporarily for risk, integrity or operational reasons. See Temporary Market Restrictions.
Trading Thin Markets Sensibly
Thin markets are allowed, and some traders deliberately work in them. If you do:
- Expect wider estimated slippage. A small order is a larger share of a small book, so the estimated price impact is proportionally larger. And that estimate is not guaranteed — see Estimated Slippage and Price Impact.
- Expect more rejections and requotes. Prices in thin markets gap more, and an order whose price has moved beyond tolerance is requoted or rejected rather than filled stale. See How Simulated Fills Are Determined.
- Watch the arithmetic against your objective. A $250 maximum position is a slow route to a $3,000 profit target, and the 40% consistency rule means you cannot make it up in one outsized day either.
- Do not try to route around the cap. Splitting one intended exposure across duplicate profiles or coordinated accounts to exceed what a single account could take is prohibited conduct — see Good-Faith Trading and Prohibited Conduct.
Still Need Help?
If a market you expected to trade is missing, or its available size looks wrong against the volume you can see, email support@fundedpredictiontrader.com with the market name and the time you checked.