Polymarket is the world's largest prediction market, a platform where people trade on the outcomes of real events, elections, interest rate decisions, wars, court rulings, sports, using shares that pay out $1 if the event happens and nothing if it does not. The price of a share doubles as a live probability estimate, which is why newsrooms now quote Polymarket odds next to polls. It settled a $3.6 billion market on the 2024 US presidential race, took a $2 billion investment from the owner of the New York Stock Exchange in late 2025, and spends 2026 living two parallel lives, a global crypto-native exchange closed to Americans and a regulated US version built on an acquired licence.
This guide covers how the platform actually works, where it is and is not legal as of September 2026, what it costs to trade, how people make and lose money on it, and what to do with the capital that sits idle between events.
The basics
Polymarket launched in 2020, founded by Shayne Coplan in New York. The global platform runs on the Polygon blockchain and settles everything in USDC, the dollar-pegged stablecoin covered in our stablecoin explainer. There is no house taking the other side of your trade. Polymarket is an order book where traders trade against each other, and prices move the way any market moves, on supply and demand.
Each market asks a yes-or-no question. Will the Fed cut rates in October? Will a given candidate win? Shares in the answer trade between 0 and 100 cents. If YES trades at 62 cents, the market is collectively pricing a 62% probability, and a YES share bought at that price returns $1 on a yes outcome, a 61% gain, or zero on a no. YES and NO prices always sum to a dollar, so buying NO at 38 cents is the identical bet from the other side. That is the entire product. Everything else, the leaderboards, the embedded charts on news sites, the commentary industry that grew around it, sits on top of those two-sided markets.
Scale is what separates Polymarket from the prediction markets that came before it. The flagship 2024 presidential market alone did $3.6 billion in volume, per Decrypt's reporting at resolution, and in October 2025 Intercontinental Exchange, the parent of the NYSE, invested up to $2 billion at a reported $9 billion valuation, positioning itself as distributor of Polymarket's probability data to institutions. Whatever one thinks of prediction markets, the infrastructure world has decided the prices they generate are data worth selling.
How markets get resolved
A prediction market is only as good as its settlement, and this is the part most new users never read. Every Polymarket market carries written resolution rules stating what counts as a yes. When the event concludes, an outcome is proposed through the UMA optimistic oracle, a smart contract system in which the proposer posts a $750 bond in USDC, per Polymarket's own documentation. The proposal then sits in a challenge window of two hours. If nobody disputes it, it stands, winning shares redeem at $1 each, losing shares go to zero, and the market closes. If someone disputes, the question escalates into UMA's dispute process, where tokenholders vote on the outcome.
The design works well for clean questions and has produced famous fights over messy ones. A market whose rules are ambiguous can resolve against what most traders assumed they were betting on, and the oracle's tokenholder voting has itself been accused of favouring large holders in contested resolutions. The practical lesson for a trader is unglamorous. Read the resolution rules before buying, not after, because you are not betting on the event, you are betting on the rules' description of the event.
Is Polymarket legal, and can Americans use it
The legal story explains why the platform exists twice. In January 2022 the CFTC ordered Polymarket's operator to pay a $1.4 million penalty for offering off-exchange event binary options without registration, and the platform blocked US users. Growth since then came from everywhere else, which is how a New York company built its product around excluding Americans.
The way back in was bought, not litigated. Polymarket acquired QCEX, a CFTC-licensed derivatives exchange, for $112 million in 2025, and launched Polymarket US on that licence as a federally regulated exchange that self-certifies products with the CFTC the way any US derivatives venue does. The waitlist came off in mid 2026, per industry coverage. So as of September 2026, Americans can legally trade a regulated Polymarket with a narrower market menu, while the global site remains off limits to them.
Outside the US the map is a patchwork trending hostile. Singapore banned Polymarket outright in January 2026 as unlicensed gambling, with penalties that reach individual users, and several other jurisdictions restrict access. Our analysis of the Polymarket ban goes into why regulators keep classifying prediction markets as gambling regardless of the blockchain underneath. Before funding an account from anywhere, the question is not whether Polymarket works in your country but whether using it is legal there, and that answer is yours to verify, not the platform's.
What it costs
Older guides still describe Polymarket as fee-free, and that era is over. Per its fee documentation, the platform now charges takers, meaning traders who hit an existing quote, a fee proportional to expected profit, at rates from 4% on politics and finance markets to 7% on crypto markets. Geopolitical markets stay free, and makers, traders whose resting orders provide the liquidity, pay nothing. Those fees fund rebate programs that pay market makers daily. There are still no Polymarket fees to deposit or withdraw USDC, though the on-ramp you use may charge its own.
In practice a 50 cent share carries a fee of about 1 to 1.75 cents depending on category. Small per trade, meaningful at volume, and worth knowing before you assume the odds you see are the odds you get.
How people actually make money on it
Strip the novelty away and Polymarket is a zero-sum market minus fees. Every dollar a winner collects is a dollar someone else lost. People who consistently profit fall into three groups. Traders with genuine information edge, who know a domain well enough to price it better than the crowd. Market makers, who quote both sides, collect the spread and earn the platform's maker rebates. And arbitrageurs, who trade price gaps between Polymarket, other venues and bookmakers, the same discipline our arbitrage explainer covers in a different market.
Everyone else is the counterparty. That is not a criticism of the product, it is what a market is, but it should reframe the expected value of casual betting. A prediction market position is speculation with a hard time limit and a resolution rule, not an investment, and sizing it like savings is the classic mistake. Financial risk on these platforms can at least be priced. As our regulatory analysis argued, the legal risk of using them from the wrong jurisdiction cannot.
The capital that waits
One structural cost gets no attention in Polymarket guides. Trading capital spends most of its life idle. USDC sits in your wallet waiting for a mispriced market, or piles up after a win, earning exactly nothing either way. For an active trader that idle majority is the price of readiness. It does not have to be a total write-off.
Stablecoins parked outside the market can earn a published rate. EarnPark pays up to 10% APY on USDC as of September 2026 as a base rate for every account, one the PARK token can only boost rather than gate, with daily payouts and an instant-withdrawal strategy option for money that needs to stay deployable. The rate calculator models the payout against any balance. The comparison of where stablecoins earn covers the wider field, and the custody guide explains the trade-off you make whenever coins leave your wallet. Speculation and yield are different tools. The traders who last tend to know which bucket each dollar is in, and you can start earning on the yield bucket in minutes.
FAQ
Is Polymarket legal in the US?
The global polymarket.com remains closed to US users under the platform's 2022 CFTC settlement. Polymarket US, a separate exchange running on the CFTC-licensed QCEX platform the company acquired, is legal for Americans and fully open since mid 2026, with a smaller market selection than the global site.
How does Polymarket make money?
Historically it ran without trading fees while growing. As of 2026 it charges takers a fee of 4% to 7% of expected profit depending on market category, funds maker rebates from that revenue, and sells probability data distribution through its partnership with Intercontinental Exchange.
Can you actually win money on Polymarket?
Yes, and every dollar won is lost by another trader. Consistent winners tend to be domain experts, market makers earning spread and rebates, or arbitrageurs. For casual users it is entertainment-grade speculation and should be sized accordingly.
What happens if a market resolves in a way traders dispute?
Resolutions go through the UMA optimistic oracle. A proposed outcome can be challenged within two hours, escalating to a tokenholder vote. Contested resolutions have gone against trader consensus before, which is why reading a market's written resolution rules before trading matters more than any odds screen.