Prediction Markets

Prediction markets have gone from academic experiment to one of the most talked-about corners of online betting — and they’re a natural fit for gamers who already like to back their read on an outcome. This guide explains what prediction markets are, how they work, whether they’re legal, how they differ from sports betting, and the biggest platforms operating today.

What are prediction markets?

Prediction markets are online marketplaces where participants buy and sell contracts tied to the outcome of a future event. These contracts — often called event contracts — gain or lose value depending on whether a specific, clearly defined outcome happens. Because traders are constantly buying and selling, the price of a contract updates in real time and acts as a market-based estimate of how likely that outcome is.

The idea rests on the “wisdom of crowds”: when many people with different information and incentives trade on a question, the resulting price often forecasts the outcome more accurately than a single expert or a traditional poll. The Iowa Electronic Markets, launched by the University of Iowa in 1988, famously predicted US presidential elections more accurately than opinion polls — and it’s still the oldest running online prediction market.

How do prediction markets work?

The mechanics are simple once you break them down. Here’s how prediction markets normally work:

1. An event is defined. A specific question with a verifiable, usually yes-or-no outcome (e.g. “Will Team A win the final?”).
2. Contracts are listed. Each outcome gets a tradable contract that pays a fixed amount — commonly $1 — if that outcome occurs.
3. Participants trade. Buyers and sellers transact based on their expectations, and prices shift with supply and demand as new information arrives.
4. The event resolves. Once the outcome is known and confirmed by an agreed source, trading stops.
5. Contracts settle. Winning contracts pay out their fixed value (e.g. $1); losing contracts expire worthless ($0).

Crucially, on a true exchange-style prediction market, participants trade directly with one another. The platform just facilitates trades and takes a small fee — it doesn’t take a side of the bet. That’s a key difference from a traditional bookmaker.

How prices and probabilities work

Prices are usually shown as a value between $0 and $1, which you can read as a probability. If a “Yes” contract trades at $0.40, the market implies a 40% chance of that outcome. If news pushes the price to $0.70, the implied probability rises to 70%. Those probabilities aren’t guarantees — they’re a snapshot of what traders collectively believe right now, and they shift with new information, sentiment and risk.

A quick event-contract example

Say a market asks: “Will Team A win the game?” The “Yes” contract is trading at $0.60, implying a 60% chance. You buy one “Yes” contract for $0.60 — that’s the most you can lose on it, while the most it can pay at settlement is $1.

• If Team A wins, “Yes” settles at $1 → you profit $0.40 per contract.
• If Team A loses, “Yes” settles at $0 → you lose your $0.60.

Because you can trade in and out before the event resolves, you can also sell early to lock in a gain or cut a loss — you’re not always stuck to settlement.

What kinds of events can you trade?

Prediction markets have been applied to almost anything with a clear, checkable outcome:

• Sports & esports: match winners, tournament champions, scorelines
• Economics: inflation prints, interest-rate decisions, GDP thresholds
• Politics: election results and legislative actions
• Business & tech: product launches, mergers, adoption milestones
• Pop culture: award winners, box-office results

The common thread: each event must have an outcome that can be objectively verified by a source specified in advance, so contracts can settle without dispute.

Explore more prediction markets guides

Beyond the basics above, we’ve broken down specific platforms, categories and trading topics in more depth:

Prediction markets vs sports betting

They can feel similar — you’re putting money on an outcome — but they work differently, and the differences matter:

• Who’s on the other side: On an exchange-style prediction market you trade against other users, and the platform stays neutral. A sportsbook sets the odds and takes the other side of your bet, building a margin (the “vig”) into the price.
• Price = probability: A prediction-market price is a live, transparent probability. Bookmaker odds bake in the operator’s margin, so they’re not a clean probability read.
• Exiting early: Prediction markets usually let you sell your position before the event ends; many sports bets you’re locked into (beyond limited cash-out offers).
• Scope: Sportsbooks focus on sports; prediction markets cover any verifiable event.
• Regulation: In the US, prediction markets sit under federal derivatives rules (the CFTC), while sports betting is licensed state by state.

For anyone who already follows the esports scene, prediction markets are a natural next step — and we dig into that overlap in our guide to esports prediction markets.

Are prediction markets gambling?

It’s a genuinely debated question. Functionally, event contracts are short-term, all-or-nothing bets on uncertain outcomes, which looks a lot like gambling — and US regulators have argued exactly that in court. Legally, though, regulated prediction markets are treated as event-contract (derivatives) trading venues, not casinos or sportsbooks. That’s part of why they can operate under federal rules where some other betting can’t.

The practical takeaway: whatever the label, the risk profile is closer to gambling than to long-term investing. Treat it accordingly — more on that in the risks section below.

Are prediction markets legal, and how are they regulated?

In the United States, prediction markets are primarily overseen at the federal level by the Commodity Futures Trading Commission (CFTC), which regulates them as venues for trading event contracts — essentially derivatives whose value depends on a future event. Platforms approved as Designated Contract Markets (DCMs) must meet strict requirements around market integrity, transparency, trade monitoring and customer protection, and are subject to ongoing oversight.

State law adds another layer. Some states classify event contracts under gaming or consumer-protection rules, which means availability can vary by state — a couple of states have moved to restrict them entirely, and several others have active legal disputes, as the picture continues to evolve through 2026. Outside the US, crypto-based platforms operate globally in jurisdictions that permit them.

Bottom line: the rules are real but still shifting, so always check what’s legal where you live and stick to regulated, registered platforms — unregistered offshore sites offer little or no protection.

The biggest prediction markets and platforms

A quick orientation to the best-known online prediction markets today:

• Polymarket — a crypto-based platform widely considered the largest prediction market in the world, covering politics, economics, sports, financial markets and pop culture.
• Kalshi — believed to be the largest prediction market in the US, with a broad range of event contracts across politics, economics, sports and more.
• PredictIt — a long-running platform focused on political questions.
• Iowa Electronic Markets — the pioneering academic market from the University of Iowa.
• Broker & crypto-app access — several mainstream apps now offer event contracts through partnerships (for example via ForecastEx or Kalshi), bringing prediction markets to existing trading and crypto accounts.

Want the full, up-to-date comparison — fees, available markets, payouts and sign-up? See our dedicated guide to the best prediction market platforms. For crypto-native platforms like Polymarket, our crypto betting and crypto casino hubs are worth a look too.

The risks and limitations to know

Prediction markets can be genuinely informative, but they carry real risks:

• Total loss: contracts settle at $1 or $0, so a losing position expires worthless — there’s no partial recovery.
• Shifting rules and taxes: platform rules, legality and tax treatment are still evolving and can change under you.
• Manipulation and insider information: unlike stock markets, prediction markets have limited protections against people trading on non-public information, and thin markets can be moved by a few large traders.
• Liquidity: in quiet markets it can be hard to trade at the price you want, or to exit a position.
• Behavioural traps: herding, overconfidence and chasing losses distort decisions — the same pitfalls as any form of betting.

Frequently asked questions

What are prediction markets in simple terms?

They’re platforms where you trade yes/no contracts on future events. If your side wins, the contract pays a fixed amount (often $1); if it loses, it pays nothing. The live price reflects the crowd’s estimated probability of the outcome.

How do prediction markets work?

An event with a clear outcome is defined, contracts are listed for each result, traders buy and sell them, and once the event resolves the winning contracts settle at their fixed value while losing ones expire worthless.

Are prediction markets legal?

In the US they’re regulated federally by the CFTC as event-contract venues, but state-level availability varies and is still evolving. Elsewhere, crypto-based platforms operate where local law allows. Always check your own jurisdiction and use regulated platforms.

Are prediction markets gambling?

Legally they’re treated as derivatives trading rather than gambling, but functionally they’re short-term, all-or-nothing bets, so the risk is closer to gambling than investing. Approach them as speculative entertainment.

What’s the difference between prediction markets and sports betting?

On a prediction market you trade against other users at a price that equals the implied probability, and you can usually exit early; a sportsbook sets the odds, takes the other side and builds in a margin. Prediction markets also cover far more than sports.

18+. Prediction markets and betting involve financial risk — never wager more than you can afford to lose, and treat any winnings as entertainment, not income. If gambling stops being fun, seek support from a problem-gambling helpline in your country.