Legacy fees (/api/v1/fees/*)
Used for markets created before April 2025.
Formula: fee = feeRate × p^exponent
Where p is the average price of the trade.
| Category | feeRate | exponent | Maker rebate |
|---|---|---|---|
| Crypto (intraday) | 25% | 2 | 20% |
| Sports (SEA, NCAAB) | 1.75% | 1 | 25% |
April 2025 fees (/api/v1/new_fees/*)
Applies to markets created under Polymarket’s updated fee structure.
Formula: fee = C × feeRate × p × (1 − p)
Precision: 5 decimal places.
| Category | feeRate | Maker rebate |
|---|---|---|
crypto | 7.2% | 20% |
sports | 3.0% | 25% |
finance | 4.0% | 25% |
politics | 4.0% | 25% |
economics | 5.0% | 25% |
culture | 5.0% | 25% |
weather | 5.0% | 25% |
general | 5.0% | 25% |
mentions | 4.0% | 25% |
tech | 4.0% | 25% |
geopolitics | — | — (no taker fees) |
Trade estimate endpoints
Both fee namespaces expose a/trade-estimate POST endpoint that returns the exact fee and net outcome for a given BUY or SELL trade. Provide either eventId or eventSlug to have the fee config resolved automatically from Polymarket’s Gamma API.