This guide refers to Polymarket US, the U.S. mobile app. Polymarket.com is a separate international product and isn't regulated within the U.S. Any references below to U.S. legality, signup, deposits, withdrawals, or where users in the U.S. can use the product refer to the Polymarket US app, not Polymarket.com.
Polymarket is the world’s largest prediction market, where users trade simple yes/no contracts tied to real-world events. In the U.S., that experience is available through the Polymarket US app. So, how does it work? And what should beginners know before placing their first trade?
We’ll walk through the basics. And if you’re signing up for the app, you can use our exclusive Polymarket promo code ACTIONtoDeposit $20 Get $20 Bonus, Use our Code to Skip the Waitlist!
How Polymarket Works
In the Polymarket US app, markets are presented as event contracts tied to real-world outcomes. Contract prices range from $0.00 to $1.00, and that price reflects the market’s implied probability. For example, a contract priced at $0.65 suggests the market sees roughly a 65% chance of that outcome happening. If your position resolves correctly, it settles at $1.00 per contract. If it doesn't, it settles at $0.00.
Rather than betting against a house, users are trading in a market where prices move based on what other participants are willing to buy and sell. The goal is to decide whether the market is pricing the outcome correctly, or missing something.
Step 1: Sign Up
Use our links to sign up for the Polymarket US mobile app and enter the promo code ACTION during the approved signup flow. To get started in the U.S., download the app, create your account, complete identity verification, and follow the in-app onboarding process before making a deposit or withdrawal.
Step 2: Add Funds
Once your account is set up, add funds using the payment methods currently supported in the Polymarket US app. If you’re new to event contracts, starting small is the better move. A modest first deposit is usually enough to learn how pricing, order entry, and settlement work without overcommitting.
Step 3: How Pricing Works
Contract pricing is simple: every contract is priced between $0.00 and $1.00, representing probability. A YES contract at $0.72 implies a 72% market probability, while a NO contract on that same market would be priced at $0.28. Together, those prices add up to $1.00.
Here’s how that works in practice:
| Scenario | If You’re Right | If You’re Wrong |
|---|---|---|
| Buy YES at $0.72 (100 contracts = $72) | Contracts resolve to $1.00. Profit = $28. | Contracts resolve to $0.00. Loss = $72. |
| Buy NO at $0.28 (100 contracts = $28) | Contracts resolve to $1.00. Profit = $72. | Contracts resolve to $0.00. Loss = $28. |
Long shots cost less because they’re seen as less likely. Favorites cost more because the market assigns them a higher probability.
Some markets may include more than two possible outcomes. In those cases, pricing should be read according to the contract structure and resolution terms shown in the market.
Step 4: Place Your First Trade
Look at the markets currently available in the Polymarket US app and start with higher-liquidity markets when possible, since tighter pricing usually makes entry and exit easier.
- Choose your side: YES or NO
- Set your price: what you’re willing to pay per contract
- Set your quantity: total cost equals price × quantity
- Submit your order once you’re comfortable with the terms
If the app offers order types such as GTC (Good-Til-Cancelled) or FOK (Fill-Or-Kill), use the one that best matches how you want the order handled.
Polymarket's Order Book Explained: Seeing the Crowd in Real-Time
Most beginners just hit the "Buy" button, but looking under the hood at the Order Book can save you money.
The order book is a real-time list of every "Limit Order" placed by other traders. It shows you the Bid (the highest price someone is willing to pay) and the Ask (the lowest price someone is willing to sell for).
The displayed price you see on a market is usually the "midpoint" between these two. However, if you want to buy 1,000 shares at once, you might "eat through" the best prices and pay more than the midpoint.
- The Spread: This is the gap between the Bid and the Ask.
Pro Tip: Stick to high-volume markets. In the busiest markets, spreads are often tighter, which can make it easier to enter and exit positions without giving up as much on price. In thinner markets, spreads can widen fast, which means you may start at a disadvantage before the trade even settles.
What Are the Different Order Types at Polymarket? GTC vs. FOK
When you place a trade, you have several ways to execute it. Understanding these helps you control exactly how much you spend:
- GTC (Good-Til-Cancelled): This is the default "Limit Order." You set your price (e.g., $0.45) and your order sits on the book until someone takes it or you manually cancel it. Use this if you aren't in a rush and want the best possible price.
- FOK (Fill-Or-Kill): This is an "all-or-nothing" order. It tells the exchange: "Either give me all 100 shares at this price right now, or cancel my entire order." This prevents you from getting "partially filled" (e.g., only getting 5 shares when you wanted 100).
- Market Order: Technically a limit order set to execute immediately against the best available prices. Use this only when speed is more important than the specific price you pay.
How to Sell Early at Polymarket
Unlike online sports betting, you're not locked in at Polymarket. If you buy YES at $0.40 and the market moves to $0.65 after a news development, you can sell immediately and pocket the difference, with no need to wait for the event to happen.
You can also cut losses early if things move against you. Track open positions in the Portfolio tab.
Some sportsbooks have early cashout policies (think bet365's early payouts), but Polymarket offers way more flexibility in the ability to exit a position early, without as many restrictions.
How Do Markets at Polymarket Resolve?
Before you buy into any market, read the resolution rules. That’s what determines how the contract will settle, not gut feel, headlines, or what people in the comments think should happen.
Each market includes its own wording, deadline, and settlement criteria, and those details matter more than most beginners expect. A contract might look straightforward, but the outcome still comes down to the exact language in the market and the source used to confirm the result. That’s why it’s smart to check the market details before you trade, especially in contracts tied to official announcements, game stats, or time-sensitive events.
If anything feels unclear, slow down and read it again. It’s a lot easier to avoid a bad entry than to realize later you misunderstood the rules.
Polymarket US App Fees: What Should U.S. Users Know?
Trading costs can vary depending on market conditions, pricing, and the payment or withdrawal methods available in the app. Even when a trade looks straightforward, your actual cost can change based on how you enter and exit the position.
For the latest details, check Polymarket’s fee schedule here.
How to Cash Out on the Polymarket US App
When you’re ready to withdraw, use the cash-out options available directly in the app. It’s also worth keeping good records as you go. Deposits, withdrawals, and trades can all matter at tax time, so if you’re unsure how any of it applies to you, talk to a tax professional before it becomes a problem.
Does the Polymarket US App Offer Rewards?
Rewards, incentives, and rebates can change over time, so the easiest way to see what’s currently available is to check the app itself. If Polymarket is offering promotions or market-specific incentives, you’ll find the details there.
Check out Kalshi's incentive programs!
Is Polymarket Legal?
Yes! For eligible U.S. users, Polymarket US operates within a regulated framework.
That said, prediction markets are still a closely watched category, and the rules around them can keep evolving. So while the app is available to eligible users, it’s still smart to check the latest access and eligibility details before signing up.
Quick Tips for Polymarket Beginners
- Start small. You don’t need to go big on day one. A smaller first deposit gives you room to learn how pricing moves, how orders fill, and how markets settle without overdoing it.
- Read the resolution rules every time. If you don’t understand exactly what counts as a winning outcome, don’t trade it yet.
- Think in probabilities, not predictions. The better question isn’t just “Do I think this happens?” It’s “Is this market pricing the odds correctly?”
- And don’t forget, you can sell early. If a market moves in your favor before it settles, you may have a chance to lock in profit without waiting for the final result.
The Bottom Line on How Polymarket Works
Polymarket is built for people who like to think in odds, not just outcomes. Prices move based on what other traders believe, which means the opportunity is in spotting where the market may be off.
It doesn’t take much to get started, and the basics make a lot more sense once you’ve placed a few trades and watched how markets move in real time. If you’re ready to try it, new users can sign up with our exclusive Polymarket promo codeACTIONand get this welcome offer: Deposit $20 Get $20 Bonus, Use our Code to Skip the Waitlist!
Now that you know how Polymarket works, check out this beginner's guide to Kalshi.
