Fees

Merlin charges a single trading fee that scales with market uncertainty — highest around $0.50 and tapering to zero at the edges.

Fee curve: per-share fee versus market price, peaking near $0.50

Formula

fee = shares × 0.07 × price × (1 − price)

price is the outcome’s market price (0–1, which is also its implied probability). shares is the number of contracts filled. Fees are charged in pUSD — Polymarket’s stablecoin, backed 1:1 by USDC.

The fee applies to filled market and limit orders, including copy-trading auto-fills. No fee on unmatched or cancelled orders.

Cashback

A percentage of every fee you pay flows back to you as cashback — starting at 5% and going up to 25% as your trading volume grows. See Cashback for the full tier ladder.