What Is Polymarket & How Does It Work?

A prediction market is a place where people buy and sell shares in the outcome of real-world events. Each share is a contract: if the event happens, the share is worth $1; if it doesn't, the share is worth $0.

The price of that share — somewhere between $0.00 and $1.00 — is the market's collective estimate of probability. A YES share trading at $0.42 means the market thinks there's a 42% chance the event happens. The closer to $1, the more likely; the closer to $0, the less likely. In American odds language, $0.42 is roughly +138; in European decimal odds, about 2.38.

Why this works: traders who think the market is wrong have a financial incentive to push the price toward what they believe is true. Decades of academic research find that prediction-market prices consistently outperform polls, pundits, and individual experts — especially for political and economic outcomes. New to the concept? Read our prediction markets for beginners guide for the longer version.

Polymarket prices reflect real-time probability estimates driven by supply and demand. Each YES share is priced between $0.01 and $1.00 — a share at $0.65 means the market collectively estimates a 65% chance the event occurs. Prices update continuously as traders buy and sell based on new information.

Polymarket runs an order book for every market. Buyers post limit orders ("I'll pay 38 cents for 100 YES shares") and sellers post the opposite ("I'll sell 100 YES shares at 42 cents"). When the prices cross, a trade executes.

Because each YES share pays exactly $1 if the event happens, anyone who thinks the event is more likely than the current price will buy — pushing the price up — until the price matches their estimate. Anyone who thinks the event is less likely will sell. This back-and-forth between informed traders is what turns the price into a probability estimate.

The mechanism is roughly the same on every major prediction market platform. Polymarket's edge is depth — high-volume markets like presidential elections, Super Bowls, and Federal Reserve decisions tend to have penny-tight bid-ask spreads because the order book is thick enough to absorb large trades without much slippage.

Polymarket makes money primarily through selective platform fees on certain markets, interest on idle deposits, and revenue-sharing with market makers — not from standard trading fees, which are often 0% maker / 0% taker for retail users. The full breakdown:

• Selective platform fees. Some market types or large institutional flows carry small fees. Always check polymarket.com's help center for current rates — the fee structure has changed multiple times.
• Spread on pUSD ↔ USDC conversions. When you deposit, your USDC is wrapped to pUSD, Polymarket's internal collateral token. Wrap and unwrap can carry small spreads.
• Institutional & liquidity arrangements. Polymarket is the largest source of prediction-market data globally; data partnerships and institutional liquidity provider arrangements generate revenue.
• Investor capital. Polymarket has raised from Founders Fund, Vitalik Buterin, and other crypto-native investors. The company is well-funded and has not historically optimized for short-term fee revenue.

Bottom line: Polymarket is much closer to a "free trading" model than to a traditional sportsbook with embedded vig. The cost you actually feel is spread and slippage, not stated fees.

You can deposit on Polymarket using a debit card, bank transfer, or USDC on the Polygon network. All deposits convert to pUSD, the platform's 1:1 USDC-backed collateral token. To withdraw, you send pUSD back to any Polygon wallet as USDC — gas costs under $0.50. Fiat off-ramps are available in some regions through partner providers.

• Debit card (in supported regions) — Polymarket integrates a fiat-on-ramp partner. The fee depends on the partner.
• Bank transfer (limited regions) — similar partner-based flow.
• Crypto transfer — send USDC on the Polygon network to your Polymarket deposit address. Sending USDC on Ethereum mainnet, Solana, or any other chain will not credit your account; recovery is possible but not guaranteed.

Once deposited, your balance is held inside the platform as pUSD — Polymarket's 1:1 USDC-backed collateral token.

Withdrawing reverses the flow. From the withdrawal screen, you can send your pUSD balance back to USDC on Polygon, to any wallet you control. Some regions support direct fiat off-ramps; most don't. The Polygon gas fee on a self-custody crypto withdrawal is typically under $0.50.

Polymarket does not custody fiat directly — fiat off-ramps go through partner providers, who set their own KYC requirements.