Fees & Costs

This page explains what a trade costs on BOOPOLY and how each figure on the order panel is calculated.

The short version: there is no gas fee (gas is sponsored). A limit order that fills as a maker costs nothing. On market (taker) orders your real cost is a small platform fee, Polymarket's own taker fee, and price slippage.

Note

Before you confirm, the order panel shows the full picture: on a buy, Total cost is the order amount plus all estimated fees; on a sell, You receive is the proceeds after estimated fees. Fee rates are set on-chain and may be updated over time, and on thin or fast-moving books a market order's slippage can differ from the estimate.

#The two fees

Two separate fees can apply to a fill. Both are applied on-chain by the exchange; BOOPOLY doesn't deduct anything itself. It estimates them in the cost breakdown so the total you see matches what leaves your wallet.

1. Platform fee (ours). A flat percentage of your order amount (shares × price), charged only on taker fills:
   • Market (taker) orders — 0.5%
   • Limit (maker) orders — none (0%)
2. Polymarket taker fee (theirs). Polymarket's own fee, charged only on taker fills — maker orders pay none. It varies by market and price (see below).

On a buy both fees are added to what you pay; on a sell they come out of your proceeds.

Note

A limit order that rests and fills as a maker pays no fees — no platform fee and no Polymarket taker fee. A limit order priced through the book (a buy at or above the best ask, a sell at or below the best bid) fills at once as a taker and is charged like a market order.

Tip

The order panel doesn't list the two fees separately. Hover or tap the ⓘ next to Total cost to open the Fee breakdown: Order amount, Gas (sponsored) at $0, one Fees line that already combines the Polymarket taker fee and the platform fee, and, for market orders, + slippage (varies by fill).

#When each fee applies: market vs. limit

Every order is either a taker (market) order that crosses the book and fills immediately, or a maker (limit) order that rests on the book waiting to be filled.

#How Polymarket's taker fee is calculated

For market orders, BOOPOLY estimates Polymarket's taker fee with the formula from Polymarket's official fee docs:

fee (USD) = rate × shares × price × (1 − price)

Because of the (1 − price) term, this fee as a percentage of your notional is rate × (1 − price) — larger on cheap (long-shot) outcomes and shrinking toward zero as a price approaches $1.

The rate is the market's own fee rate as published by Polymarket, and some markets charge no taker fee at all. Rates differ even within a category — NFL and college-football markets, for example, use 3%. When a market doesn't publish a rate, BOOPOLY falls back to its category:

Note

These rate values are the multiplier in the formula, not the percentage of your trade. Example: a 5% rate on a share bought at $0.50 costs 0.05 × 0.50 × 0.50 = $0.0125 per share, i.e. 2.5% of the $0.50 notional.

#Worked example (market buy)

Buy 5 shares of a sports outcome with a 5% rate at $0.8775 (order amount ≈ $4.39):

The same trade as a limit order that rests and fills as a maker would pay no fees — no platform fee and no Polymarket taker fee.

#Slippage

Slippage is the difference between the price you see and the price you actually get, because a market order works through the order book from the best price outward (upward for a buy, downward for a sell). On a deep, liquid market it's negligible; on a thin market a single order can noticeably move the fill price.

• Market orders carry slippage — the trade-off for immediate fills. The panel's Max slippage setting (default 2%; 1–5% shown, with 10 / 20 / 40% further along) rejects a market fill worse than that % from the current price instead of executing it.
• Limit orders don't: you set the exact price and the order rests until the market comes to you (or you cancel). The trade-off is that a limit order may fill partially or not at all.

Tip

On thin or fast-moving markets, a limit order is often the better fit: it avoids slippage, Polymarket's taker fee and the platform fee.

#Gas is sponsored

On-chain gas is sponsored — transactions go through a gasless relayer — so:

• You never buy or hold MATIC/POL for normal trading.
• On-chain approvals and order placement cost you no gas.
• Collateral wrapping (USDC.e → pUSD) happens automatically in the background at no extra charge.

Note

The one place POL comes up is the optional, self-custody rescue tool, which moves your funds out independently of the BOOPOLY site. It runs on your own computer and needs a little POL for gas; it is not part of normal trading. See Security.

#On-chain transparency

Orders placed through BOOPOLY are real Polymarket CLOB orders, signed from your own wallet and settled on Polygon. That means:

• Your fills, positions, and settlements are verifiable on-chain and on Polymarket's own data feeds.
• Both fees are applied by the exchange on-chain; the platform fee is attributed to BOOPOLY's builder code.
• There is no hidden spread or price markup on top of the Polymarket price — what you pay is the book price, the fees above, and (for market orders) slippage.

#Requirements

• A funded deposit wallet — see Deposit & Withdraw.
• Enough collateral to cover shares + estimated fees on a market buy; the panel shows the total debit before you confirm.
• No POL/MATIC balance is required for normal trading (gas is sponsored).

#Related

• Placing a Trade
• Orders & P&L
• Rewards & Notifications — maker rewards
• Copy Trading Reference
• Security