Position size determines how much of your balance is exposed to a single market, and it directly affects both your risk and your path to qualifying trades.
On Catalyst, the maximum you can trade in a single market is $1,500. This is a total cap across every trade you place on that market. Open positions and closed ones both count toward it. It limits how much you can put at risk on one market; it does not limit how many markets you can trade.
The $1,500 cap applies per market. You may trade as many markets as you'd like.
The $1,500 cap also applies across time windows. On recurring short-window markets like BTC Up or Down, once you reach $1,500 of total trading in a specific window, you will not be able to re-enter that same window after closing. You can trade the next available window once it opens.
What happens if you try to exceed the cap
If an order would push your total trading on a market above $1,500 — open and closed positions combined — the platform blocks the order before it goes through. You will see an error message, the order will not partially fill and no trade will be placed. Reduce the size and resubmit.
Example: You buy $1,000 of YES contracts in "Will the ECB cut rates in June?" and later close the position. That $1,000 still counts toward the cap on this market, even though you no longer hold anything. You can place up to $500 more on this market — if you try to place $600, the order is blocked. Enter $500 or less and resubmit.
How contract price affects your risk
The price of the contract determines your maximum loss per contract if the trade goes against you.
You buy | At price | Max loss per contract if wrong |
YES | $0.80 | $0.80 |
YES | $0.40 | $0.40 |
NO | $0.20 | $0.20 |
Lower-priced contracts have lower downside per contract, but they also reflect lower implied probability of winning.
Balancing size against the Max Loss
Every position you take affects how close you are to the max loss floor. A $1,500 position that resolves at $0.00 is a $1,500 realized loss, which is more than your entire $1,000 Max Loss buffer. On Level 2 and above, a single realized loss that size would end your level on its own, no matter where your high-water mark sits.
Before sizing a position, consider:
How far is your current Realized Balance from the Max Loss floor?
How many qualifying trades do you still need?
How confident are you in this market?
How liquid is the market? Will a larger order cause slippage?
A qualifying trade is your combined realized P&L on a single market reaching $500, so it doesn't take one max-size position to earn one. You can trade a market multiple times and let the closed trades net toward $500. Larger positions clear it on less price movement but draw down your max loss buffer just as fast if they go against you. Smaller or staged positions protect the buffer but need more net movement to qualify. The right approach depends on your read of the market and how much buffer you have left.