On Nimb, a trade costs Polymarket's platform taker fee (zero in some categories), a small Nimb builder fee and the spread. Nimb folds both fees into the amount you type, so $100 means $100 all-in, and the break-even price on the ticket already includes them.
What does a trade cost on Nimb?
| Cost | Who sets it | When you pay it | Shown on Nimb as |
|---|---|---|---|
| Platform fee | Polymarket, per market | Taker orders, buys and sells, in fee-charging categories | Included in shares and break-even |
| Builder fee | Nimb, within Polymarket's limits | Taker orders placed through Nimb, buys and sells | Included in shares and break-even |
| Spread | The market | Every order that takes liquidity | Visible as the gap between bid and ask |
| Gas | Polygon | Not for orders; see below | – |
Fees come in addition to the market price, never instead of it, but Nimb folds them into your amount rather than adding them afterwards. The ticket's job is to show the total before you sign.
What fees does Polymarket charge?
Polymarket charges a taker fee on most categories and none on geopolitics. The formula, from Polymarket's fee documentation, is:
fee = shares × feeRate × p × (1 − p)
where p is the share price. The fee is largest at 50% and shrinks towards 0% and 100%; a trade at 30% costs the same dollar fee per share as one at 70%. As a share of what you spend, it equals feeRate × (1 − p), so cheap long shots pay the most in percentage terms.
| Category (Polymarket) | Taker fee rate | Fee on 100 shares at 50% | Fee as % of spend at 41% |
|---|---|---|---|
| Crypto | 0.07 | $1.75 | 4.13% |
| Sports | 0.05 | $1.25 | 2.95% |
| Economics, Culture, Weather, Other | 0.05 | $1.25 | 2.95% |
| Finance, Politics, Tech, Mentions | 0.04 | $1.00 | 2.36% |
| Combos | 0.05 | $1.25 | 2.95% |
| Geopolitics | 0 | $0 | 0% |
Rates as published by Polymarket at the time of writing (2026-11-07). Polymarket's categories are not identical to Nimb's map categories; the ticket reads each market's own fee schedule. Some markets carry a different rate, or none during a fee holiday, so the per-market figure is the one that counts. Fees are rounded to 5 decimal places.
Do makers pay fees?
No. Polymarket charges makers no platform fee; only takers pay. A taker order fills against the book right away, like a market order. A maker order is a limit order that rests on the book until someone else fills it. Part of the taker fees is paid back to makers as rebates, and since 2026-05-28 frequent takers can also earn a tiered rebate (3% to 50% of fees, by 30-day volume). Nimb's ticket does not count rebates in its break-even.
Polymarket charges no fee to deposit or withdraw. Services you use to buy or move funds, such as an exchange or a card on-ramp, may charge their own.
What does Nimb charge?
Nimb charges a small builder fee, included in the price you see. It is how Nimb is paid: there is no subscription, no spread mark-up and no fee for using the map. More on this in independence and business model.
- It is a flat percentage of the trade's notional (shares × price), set through Polymarket's Builder Program.
- It applies to taker orders placed through Nimb, buys and sells, in every category, including fee-free geopolitics markets.
- Resting limit orders that fill as a maker pay no Nimb fee at launch.
- It is attached to your order through Nimb's builder code, and Polymarket collects it at match time.
Builder fee rates are public. Anyone can check what a builder charges at GET https://clob.polymarket.com/fees/builder-fees/<builder code>. Polymarket caps builder taker fees at 1% of notional, lets a builder change its rate at most once every 7 days, and makes each change take effect 3 days after it is scheduled.
What does "fees included" mean?
It means the amount you type is the total you pay. Nimb does not add fees on top: it buys fewer shares so that price plus fees equals your amount. The ticket computes the all-in price per share as the market price plus Nimb's builder fee plus Polymarket's taker fee for that market, then divides your amount by it and rounds the shares down.
The builder fee is not itemised on the ticket. It shows up in two places: the number of shares, and the break-even, which is the all-in price per share. A market order's all-in amount is a close estimate, not a hard cap, because Polymarket computes fees when the order matches. See the order ticket for how this appears.
Is the spread a cost too?
Yes, and often the largest one. A buy fills at the ask, a sell at the bid. If the bid is 40% and the ask 42%, the mid is 41% and the spread is 2 points: buying and selling straight back would lose 2 points before any fee, or about $4.74 on 237 shares. On a thin book a large order also walks through several price levels, which is slippage. Nimb's market selection drops markets with a spread above 4 points unless they have $10k of depth, but spreads still move. See spread and order book depth.
Are there fees when I sell?
Yes. A sell that fills at once is a taker order, so Polymarket's taker fee applies in fee-charging categories, and Nimb's builder fee applies to sells placed through Nimb. Both are taken out of what you receive. Holding to resolution has no trading fee: winning shares are redeemed for $1 each. See selling and closing a position.
How do fees change my break-even?
Worked example: a $100 Yes order at 41% in an illustrative politics market (Polymarket rate 0.04).
| Line | Value |
|---|---|
| You pay, all-in | $100.00 |
| Shares bought, all fees included | 237.12 |
| You receive if Yes | $237 |
| Break-even, all fees included | 42.2% |
Polymarket's taker fee and Nimb's builder fee together move the break-even from 41% to 42.2%: buying pays off on average only if the real chance is above 42.2%. Add a 1-point spread and you need about 43% against a mid of 41%. This is why alpha, an informational edge, has to be measured after costs: a 2-point view is mostly eaten by fees and spread.
How does the category change a $100 order at 41%?
| Market type (illustrative) | Polymarket rate | Shares | Pays if right | Break-even |
|---|---|---|---|---|
| Politics, Finance, Tech | 0.04 | 237 | $237 | 42.2% |
| Sports, Culture | 0.05 | 235 | $235 | 42.4% |
| Crypto | 0.07 | 233 | $233 | 42.9% |
Shares, payouts and break-evens include all fees, Polymarket's and Nimb's, and assume the whole order fills at 41%. In fee-free geopolitics markets only Nimb's builder fee applies, so the break-even sits just above the price. Kalshi uses a similar price-dependent fee shape; see Polymarket vs Kalshi.
Do I pay gas?
Not for orders. Signing an order is an off-chain signature and costs nothing, and Polymarket settles matched trades. Setting up your Polymarket wallet and its trading approvals runs through Polymarket's relayer without gas for you. Moving funds in from another chain costs that chain's gas, paid from your own wallet.
Prediction markets are risky; you can lose your whole stake. Nothing on Nimb is financial advice. Read the risks of prediction markets before you trade.
Last reviewed 2026-11-07 · Data from Polymarket · Not financial advice · Nimb is not affiliated with Polymarket.