The Two Limits
Max open size is the most total exposure you can have open at one time, across the account — every position draws on the same allowance. Any one market is capped on top of that, and that market's 5% is a single ceiling too: everything you already hold there counts against it, so splitting one order into several does not buy extra room.
Available in a market = the lower of (your max open size − what you already have open on the account) and (5% of that market's 24-hour volume − what you already have open in that market).
Max Open Size by Stage
| Account | Evaluation max open size | Funded starting max open size |
|---|---|---|
| $25k FPT Scale | $1,000 | $500 |
| $50k FPT Scale | $2,000 | $1,000 |
| $100k FPT Scale | $3,000 | $1,500 |
Approved payouts raise the payout cap and max open size until the account reaches its maximum tier. For every milestone, see Scaling.
How Much You Can Open in a Market
Everything you have open at once counts toward max open size, added together. On a $50k evaluation account with a $2,000 max open size:
| Open now | Exposure |
|---|---|
| Market A | $800 |
| Market B | $700 |
| Market C | $500 |
| Total open exposure | $2,000 |
That account is at its limit until one of those positions is reduced or closed. Close Market C and $500 comes back — and what you can then open in a new market is the smaller of that $500 and 5% of the market's 24-hour volume:
| That market's 24h volume | 5% of it | You can open |
|---|---|---|
| $6,000 | $300 | $300 |
| $16,000 | $800 | $500 |
In the first market the market is the limit; in the second your account is.
Going back into a market you are already in works the same way, with one difference: you are measured against what is left of that market's 5%. If a market turning over $16,000 gives you an $800 ceiling and you already hold $300 there, $500 of that market's ceiling remains — so three orders of $300 do not add up to $900. The ceiling belongs to the market, not to the order.
If an Order Is Blocked
Reduce the size and submit again — that is the whole fix. An oversized order is blocked before it is accepted, so it is not a breach and not a rule violation, and nothing is recorded against your account.
You should rarely meet one. The order ticket shows what you can still open before you build the order, and a blocked order's message states the size that is available instead. Because trailing 24-hour volume moves continuously, a market's limit can change between one order and the next; the limit applied is the one in force when you submit.
Beyond the two size limits, an order can also be turned away because the market itself is thin, in resolution, or under a temporary restriction — halted, closed, resolving, disputed, stale or technically unreliable. See Market and Position Rules.
Thin Markets
A thin market has low trailing volume, so the 5% cap allows a smaller position there. It is perfectly tradeable and the dashboard labels it clearly, so you can see the constraint before you build an order. FPT may temporarily restrict or remove a market where its data quality is degraded, where it is in resolution or dispute, or where it cannot be simulated reliably. See Market Availability and Thin Markets.
Splitting a Position Is Prohibited
Meeting the limit is fine; engineering your way past it is not. Splitting a position to get around the limit is prohibited even where each individual order passes the platform's check — that includes spreading the same exposure across multiple orders, across near-identical markets, across sub-markets of the same event, or across separate FPT accounts. Choosing a market primarily because it is thin enough to move, rather than because you have a view on the outcome, is also prohibited. See Prohibited Trading Conduct.
One thing worth sizing for: your maximum is also a drawdown decision. On the $50k evaluation account a full $2,000 that resolves to zero takes you from the starting balance to the starting floor in one move. See Maximum Loss and Trailing Drawdown.