How Polymarket Works: Trading, Odds & Payouts

The Basics of Trading

Trading on Polymarket is straightforward once you understand the core mechanic. Every market poses a yes-or-no question about a future event. You express your view by buying shares on either side.

Let's say the market asks: "Will the Fed cut interest rates in June?" If "Yes" shares are trading at $0.45, that means the market currently gives it a 45% chance. If you think the probability is actually higher — say 60% — you'd buy "Yes" shares at $0.45 and profit if the Fed does cut rates.

Understanding Share Prices

Share prices on Polymarket range from $0.01 to $0.99. The price represents the market's consensus probability for that outcome. Here's what different prices mean:

• $0.01–$0.10: The market considers this outcome very unlikely (1–10% chance)
• $0.30–$0.50: Uncertain — could go either way
• $0.70–$0.90: The market considers this outcome likely
• $0.95–$0.99: The market considers this outcome near-certain

Remember: "Yes" price + "No" price always approximately equals $1.00. If "Yes" is at $0.65, "No" is at $0.35.

How to Place a Trade

Once you've funded your account with USDC (a dollar-pegged stablecoin), placing a trade is simple:

1. Browse or search for a market that interests you
2. Click on the market to view its details and current odds
3. Select "Yes" or "No" based on your prediction
4. Enter the amount you want to spend (in USDC)
5. Review the number of shares you'll receive and the average price
6. Confirm the trade

Your shares appear in your portfolio immediately. You can sell them at any time before the market resolves, or hold them until resolution.

How Payouts Work

When a market resolves (the event occurs or the deadline passes), the outcome is determined:

If you bet correctly: Each share you hold pays out $1.00. If you bought 100 "Yes" shares at $0.40 each ($40 total), and the market resolves "Yes," you receive $100 — a profit of $60.

If you bet incorrectly: Your shares become worthless. You lose the amount you originally paid.

Early exit: You don't have to wait for resolution. You can sell your shares at any time at the current market price. If prices move in your favor, you can lock in a profit early.

The Order Book

Polymarket uses a Central Limit Order Book (CLOB) powered by the Polygon blockchain. This means trades are matched like a traditional exchange rather than using an automated market maker (AMM). This provides better pricing and less slippage for traders.

You can place both market orders (executed immediately at the best available price) and limit orders (only executed at your specified price or better). Limit orders let you be patient and get a better entry price.

Fees

Polymarket charges no trading fees on most markets. The platform generates revenue through the spread between bid and ask prices. However, there may be small blockchain gas fees for deposits and withdrawals, which are typically a few cents on the Polygon network.

Understanding Volume and Liquidity

Volume is the total amount of money traded on a market over a given period. High-volume markets are generally more reliable as price signals because more people are participating. Liquidity refers to how easy it is to buy or sell without affecting the price. Deep liquidity means you can trade large amounts without significant price impact.

On Polymarket, the most popular markets (presidential elections, major crypto milestones) often have millions of dollars in liquidity, while niche markets may have much less.