On Polymarket the counterparty to your trade is another trader: when you buy Yes, someone else either sells Yes or buys No, and the exchange's contracts match the orders and hold the collateral; there is no house taking the other side. If no order matches, a new pair of Yes and No shares is created from $1 of pUSD, one for each buyer. Nimb sends your order to that same order book from your wallet.
How does matching work?
| You do | Matched against | Result |
|---|---|---|
| Buy Yes at 41¢ | A seller of Yes at 41¢ | Shares change hands |
| Buy Yes at 41¢ | A buyer of No at 59¢ | $1 of pUSD mints one Yes and one No share |
| Sell Yes at 41¢ | A buyer of Yes at 41¢ | Shares change hands |
| Sell Yes at 41¢ | A seller of No at 59¢ | The pair is merged back into $1 of pUSD |
Source: Polymarket: prices and order book. Because every share is backed by $1 of collateral at creation, winners are paid from the losers' stakes, not from the platform. Event contracts.
Who are the other traders?
A mix: people with views, people hedging other exposure, and market makers who quote both sides for the spread and Polymarket's rebates. When you trade against a market maker, you are not trading against "the house": the market maker can lose too, and you can see the largest positions on Nimb's holder list.
Frequently asked questions
Does Polymarket bet against you?
No. Polymarket matches orders between users and earns fees; it is not the counterparty.
What if nobody takes the other side?
Your limit order waits in the book. A market order fills only against what is there, or fails.
Last reviewed 8 November 2026 · Data from Polymarket · Not financial advice · Nimb is not affiliated with Polymarket.