# polymarket.health — Full Lesson Bundle > Independent live status mirror for Polymarket, Kalshi, Manifold, PredictIt, Limitless, Futuur and Myriad, plus a free Prediction Markets 101 curriculum. > Not affiliated with any platform listed. Publisher: polymarket.health Canonical: https://polymarket.health Lesson index (JSON): https://polymarket.health/api/public/articles.json Updated: 2026-06-17 License: Content may be cited with attribution to polymarket.health and a link back to the source URL. --- # Lesson 01 — What Is a Prediction Market? A Beginner's Guide Module: Foundations URL: https://polymarket.health/learn/what-is-a-prediction-market Published: 2026-01-05 Reading time: 6 min > Prediction markets let people trade contracts on the outcome of real-world events. Here's how they work, why they're often more accurate than polls, and where to trade. A prediction market is an exchange where the things being traded are not stocks or commodities but contracts that pay out based on the outcome of a future event. If you buy a contract for "Candidate X wins the 2028 election" at $0.40 and Candidate X wins, the contract pays $1.00. If they lose, it pays $0.00. The price of the contract — between $0 and $1 — can be read directly as the market's implied probability of the event. This makes prediction markets unique. A poll asks a thousand people what they think; a prediction market asks anyone with money on the line what they're willing to bet. Because traders lose money for being wrong, prediction-market prices tend to incorporate information faster and more accurately than polls or pundit forecasts. ## A short history Informal prediction markets have existed for centuries — the Iowa Electronic Markets, run by the University of Iowa since 1988, is one of the oldest formal ones. After the rise of crypto, real-money prediction markets exploded in scale. Polymarket, launched in 2020, traded billions of dollars during the 2024 US presidential election. Kalshi, regulated by the CFTC, brought event contracts to the regulated US derivatives market in 2021. ## Why they're often more accurate than polls Markets aggregate information. Anyone who knows something — a tracking pollster, a campaign operative, a sports trainer — has an incentive to act on it. Their trades move the price. Decades of academic research (Wolfers and Zitzewitz, Hanson, Arrow et al.) have found that prediction markets generally outperform expert forecasts. They aren't infallible. Markets can be thin, manipulated, or biased by retail enthusiasm. But over enough markets and enough time, they're a remarkably good probability machine. ## Where to trade Polymarket is the largest crypto-based prediction market — you deposit USDC and trade. Kalshi is the leading US-regulated platform, where you deposit USD via ACH. Manifold uses play-money. PredictIt is an academic political market. Each has tradeoffs in liquidity, regulation, fees, and contract variety. Their status pages — like this one — let you check whether the platform is online before you try to trade. ## Frequently asked **Q: Are prediction markets the same as betting?** A: Legally they're treated as derivatives or event contracts, not gambling, in regulated venues like Kalshi. Economically the mechanics are similar but the products are structured as binary options. **Q: Can I make money on prediction markets?** A: Yes, but most participants lose money to fees and the smartest traders. Treat them as information aggregators first, profit-seeking instruments second. --- # Lesson 02 — How Prediction Market Prices Map to Probabilities Module: Foundations URL: https://polymarket.health/learn/prices-as-probabilities Published: 2026-02-04 Reading time: 5 min > A market price of $0.62 on a binary contract reads directly as a 62% implied probability — but with subtle caveats around fees, spread, and risk neutrality. Every binary prediction contract pays $1 if the event happens and $0 if it doesn't. If the market is pricing the contract at $0.62, traders collectively believe the event has roughly a 62% chance of happening. This direct mapping — price equals probability — is what makes prediction markets so legible. ## The basic math Expected value = (probability of yes) × $1 + (probability of no) × $0. If the market price equals expected value, the price IS the probability. A risk-neutral trader who thinks the true probability is 70% will buy any contract priced below $0.70. ## Where the translation gets noisy Fees, spread, and time value all push price away from the true probability. On Kalshi, a fee on profits means a fair price is slightly above the true probability for yes-buyers. On Polymarket, a wide bid/ask spread on illiquid markets means there's no single "price" to read. Long-dated markets also discount for opportunity cost — capital tied up for a year should earn a return, so contracts on far-future events trade below their true probability by roughly the risk-free rate. ## Reading aggregated odds When media outlets cite "a 62% chance according to Polymarket," they're reading the midpoint of the bid/ask. That's a fine first approximation, but the spread tells you how confident the market is in its own number. A market quoting 60/64 is far less certain than one quoting 61.8/62.2. ## Frequently asked **Q: Does a $0.50 contract mean a coin-flip?** A: Usually yes — but check liquidity. A $0.50 mid on a thin market may just mean nobody has formed a strong view. **Q: Why do Polymarket and Kalshi sometimes show different probabilities?** A: Different user bases, fee structures, and access restrictions cause persistent gaps. Arbitrageurs narrow them but rarely close them entirely. --- # Lesson 03 — Order Books vs AMMs in Prediction Markets Module: Foundations URL: https://polymarket.health/learn/order-books-vs-amms Published: 2026-02-08 Reading time: 6 min > Polymarket and Kalshi use central limit order books; Limitless and other onchain newcomers use AMMs. Here's what changes for the trader. Two main mechanisms match prediction-market trades: central limit order books (CLOBs) and automated market makers (AMMs). Polymarket and Kalshi use order books. Limitless and some onchain markets use AMMs. The same contract can feel very different depending on which is under the hood. ## Order books, briefly Traders post limit orders at specific prices. A buy order at $0.61 sits in the book until someone is willing to sell at $0.61 or less. Order books offer fine-grained price discovery and tight spreads on liquid markets, but go thin or wide on long-tail markets that lack natural counterparties. ## AMMs, briefly An AMM is a pool of liquidity priced by a formula. Buying yes shares from the pool moves the price up; selling moves it down. Trades always execute against the pool, so even markets with no human counterparty have continuous prices. The tradeoff: large trades move the AMM price meaningfully (slippage). On thin markets, slippage can be larger than an order-book spread would have been. ## Which matters for you? For trades under $500 on top markets, the difference is small. For large positions, an order book on Polymarket or Kalshi usually fills better. For tiny long-tail markets, an AMM may be the only place that gives you a price at all. ## Frequently asked **Q: Which is cheaper, AMM or order book?** A: Order books on deep markets; AMMs on thin markets where book depth is essentially zero. **Q: Can the same market use both?** A: Yes — some platforms layer an order book on top of AMM liquidity to combine the strengths of each. --- # Lesson 04 — Why Prediction Markets Often Beat Polls Module: Foundations URL: https://polymarket.health/learn/why-markets-beat-polls Published: 2026-02-12 Reading time: 6 min > Decades of research show that prediction markets typically outperform expert polls. Here's why — and when polls win. It's a stylized but well-supported finding: prediction markets, in aggregate and over time, produce more accurate forecasts than expert polls. Wolfers and Zitzewitz showed this for elections; Berg, Forsythe, and Rietz showed it for political markets; the Good Judgment Project showed it for geopolitics. ## Why markets aggregate information better Polls ask people what they think. Markets ask people what they'd bet. The first answer is cheap; the second has skin in the game. Information that would never make it into a poll — a campaign internal, a political donor's body language, a tracking model's latest run — finds its way into a market via someone willing to trade on it. ## When polls win Polls outperform markets when the market is thin, manipulated, or biased by partisan retail flow. The 2024 US election briefly saw Polymarket pricing significantly higher for one candidate than poll aggregators predicted — a gap eventually closed by reality but at the time hotly debated. Markets also fail at unknowable events. A poll of epidemiologists is more useful than a thin novelty market on a future pandemic, even though the poll is less rigorous in form. ## How to use both Use poll aggregators for ground-truth sampling of voter intent. Use markets to see how aggressively traders are willing to put money behind that intent. The gap between the two is itself information — it tells you where the smart money disagrees with the mainstream. ## Frequently asked **Q: Have prediction markets ever been catastrophically wrong?** A: Yes — Brexit and Trump 2016 are the canonical examples. Markets priced both as unlikely; both happened. **Q: Are prediction markets manipulable?** A: On thin markets, yes — but manipulation is expensive and usually leaves an arbitrage opportunity for everyone else. --- # Lesson 05 — How Polymarket Works: USDC, UMA & On-Chain Resolution Module: Platforms URL: https://polymarket.health/learn/how-polymarket-works Published: 2026-01-08 Reading time: 7 min > A technical-but-readable explainer of how Polymarket processes trades, settles markets via UMA's optimistic oracle, and what can go wrong. Polymarket is a non-custodial prediction market built on Polygon (a Layer 2 connected to Ethereum). Every market is a smart contract that holds USDC and issues two tokens — one for each outcome. You buy and sell those tokens; the winning side redeems for $1 of USDC each, the losing side goes to zero. ## Order matching Polymarket uses a central limit order book (CLOB) for matching, but settlement happens on-chain. When you place a limit order it sits in an off-chain order book operated by Polymarket. When it matches, both sides sign an order and the trade settles on Polygon in a single transaction. This hybrid design gives Polymarket the speed of a centralized exchange and the custody guarantees of DeFi — your USDC never leaves your wallet without your signature. ## How outcomes get resolved When a market closes, UMA's optimistic oracle decides the outcome. Anyone can propose a result; if no one disputes within the challenge window, that result is finalized and the smart contract pays out winners. If there's a dispute, UMA token holders vote. This is usually fast and cheap, but it can fail in edge cases — ambiguous market wording, late-breaking news, or coordinated dispute attacks. Polymarket has had public controversies about resolution decisions; the on-chain history is permanent. ## Common failure modes When Polymarket goes down, it's usually one of: the front-end API (you can't see markets), Polygon RPC providers (you can see markets but transactions hang), the order matching engine (orders fill slowly), or wallet connectivity (your wallet can't sign). The status page above tracks each component. ## Frequently asked **Q: Is Polymarket legal in the US?** A: Polymarket settled with the CFTC in 2022 and geoblocks US users. Some users access it via VPN, which is against the terms of service. **Q: What chain is Polymarket on?** A: Polygon. You'll need a small amount of MATIC for transaction fees in addition to USDC for trading. --- # Lesson 06 — How Kalshi Works: CFTC-Regulated Event Contracts, USD Settlement Module: Platforms URL: https://polymarket.health/learn/how-kalshi-works Published: 2026-02-15 Reading time: 7 min > A technical-but-readable explainer of how Kalshi structures contracts, clears trades, and stays regulated as a CFTC-licensed Designated Contract Market. Kalshi is a Designated Contract Market (DCM) regulated by the Commodity Futures Trading Commission. That regulatory status is the most important thing to understand about how it works — every other design choice flows from it. ## Contracts are formally certified Every contract Kalshi lists is filed with the CFTC, either as a self-certification or a request for approval. The contract specifies precise terms: what event, what resolution source, what dates, what payout, what position limits. This bureaucratic overhead is why Kalshi's catalog grows more slowly than Polymarket's. ## Custody and clearing Customer funds sit in segregated US bank accounts. Kalshi clears its own trades through a Derivatives Clearing Organization (DCO) it operates. There is no oracle and no chain; resolution is performed by Kalshi against the contract's specified resolution source. ## Deposit / trade / withdraw Fund via ACH (free, slow), debit card (small fee, instant), or wire. Trade through the web or mobile app against Kalshi's order book. Fees are taken on profitable closes — typically 1% to 7% of profit, varying by contract. Withdrawals are ACH and settle in 1–3 business days. ## When Kalshi breaks Kalshi's failure modes are traditional-fintech failures: ACH processor delays, KYC backlogs during signup surges, identity-verification edge cases. The exchange itself is more reliable under load than crypto-rail platforms because it doesn't depend on chain throughput. ## Frequently asked **Q: Is Kalshi insured?** A: Funds sit in segregated US banks. Cash in those accounts has standard FDIC coverage up to per-bank limits; positions themselves are not FDIC-covered. **Q: Can I day-trade on Kalshi?** A: Yes — Kalshi has no day-trading restrictions, but liquidity outside flagship contracts may not support fast turnover. --- # Lesson 07 — Polymarket vs Kalshi: Regulated vs Crypto Prediction Markets Module: Platforms URL: https://polymarket.health/learn/polymarket-vs-kalshi Published: 2026-01-12 Reading time: 8 min > Polymarket and Kalshi both let you trade event contracts, but everything else — regulation, deposits, contract variety — is different. Here's the full comparison. Polymarket and Kalshi are the two most-watched prediction markets in 2026. Both let you trade binary contracts on real-world events, both saw record volume during the 2024 US election, and both regularly appear in mainstream coverage of election odds. But they are built on opposite philosophies. ## Regulation Kalshi is a CFTC-regulated Designated Contract Market (DCM). Every contract it lists has been formally certified or approved by the regulator. Customer funds are held in segregated US bank accounts. Kalshi is legal in all 50 US states. Polymarket is unregulated in the US. It settled with the CFTC in 2022 and now blocks US users. The platform operates from offshore entities; contracts settle on-chain in USDC. ## Deposit and withdrawal Kalshi accepts ACH, debit, and wire transfers in US dollars. Most deposits are instant; withdrawals settle in 1–3 business days. Polymarket requires USDC on Polygon. You'll typically bridge from Ethereum or Solana, or buy USDC directly inside Polymarket via Moonpay. There are no fiat rails. ## Contract variety Polymarket lists thousands of markets — politics, sports, crypto prices, pop culture, weather, even "will X tweet Y by date Z" novelty markets. Many of these would never get CFTC approval. Kalshi is more curated. Categories include economics, climate, elections, sports, and entertainment. Each contract requires regulatory approval, so the list grows more slowly but is more rigorous. ## Which should you use? If you're in the US and want a legal, regulated venue with FDIC-backed deposits, use Kalshi. If you're outside the US, want the widest market selection, and don't mind crypto rails, Polymarket has more liquidity. Many sophisticated traders use both. ## Frequently asked **Q: Which has more liquidity, Polymarket or Kalshi?** A: Polymarket has higher headline volume; Kalshi has deeper book depth on its largest contracts. Both vary by market. **Q: Can I arbitrage between Polymarket and Kalshi?** A: Yes — and many traders do. Equivalent contracts often diverge by a few cents, especially around news events. --- # Lesson 08 — Polymarket vs Robinhood Prediction Markets: How They Differ Module: Platforms URL: https://polymarket.health/learn/polymarket-vs-robinhood Published: 2026-06-17 Reading time: 7 min > Robinhood's event contracts vs Polymarket's on-chain markets — compare US availability, regulation, fees, contract types, and how each one actually works. Robinhood now offers prediction-market-style event contracts directly inside its brokerage app, routed through a CFTC-regulated exchange (Kalshi via the Robinhood Derivatives integration). Polymarket is a non-custodial, crypto-native market built on Polygon where you trade USDC against an on-chain order book. Both let you take a position on whether something will happen, but everything underneath — custody, regulation, fees, and what markets exist — is different. ## How Robinhood's prediction market works Robinhood does not run its own exchange. It plugs an existing CFTC-regulated event-contract venue into the Robinhood app, so US users can buy and sell Yes/No contracts on events like Fed rate decisions, elections, and major sports outcomes the same way they buy stocks. Funds sit in your Robinhood brokerage account in USD. Orders are matched on the underlying regulated exchange, and Robinhood collects a per-contract fee on top. Because it is regulated as a derivatives product, contracts are limited to events the exchange has filed and the CFTC has not blocked. Position sizes, eligible accounts, and available markets can change with little notice when regulators push back. ## How Polymarket works Polymarket is a smart-contract system on Polygon. Each market is a contract holding USDC; you trade Yes/No outcome tokens against an off-chain order book that settles on-chain. Resolution is handled by UMA's optimistic oracle, not a regulator. You hold your own keys, deposits arrive as USDC, and trades clear in seconds. Polymarket does not currently take US retail customers directly — it geoblocks US IPs and does not onboard US users through KYC. Most of its volume is international, and the catalog covers politics, crypto, sports, pop culture, and breaking news with far more markets than any regulated US venue. ## US availability Robinhood prediction markets are explicitly built for US retail. You sign up with the same brokerage account, fund via ACH, and trade within US trading hours and rules. Polymarket is the opposite: US persons are blocked at signup and IP level after the 2022 CFTC settlement. International users access it directly through a self-custodial wallet. ## Fees Robinhood charges a small per-contract fee (typically a few cents per side) on top of the underlying exchange's fees. There is no commission on opening or closing the position beyond that contract fee, and deposits/withdrawals via ACH are free. Polymarket charges 0% trading fees on most markets — you only pay the bid/ask spread and Polygon gas (usually fractions of a cent). The real cost is on the on/off ramp: converting USD to USDC and bridging to Polygon. ## Contract types and market depth Robinhood lists a curated set of regulated event contracts: Fed decisions, elections, headline economic prints, major sports. Each market has clear rules, a defined settlement source, and CFTC oversight. Liquidity on flagship contracts is deep. Polymarket lists thousands of markets across politics, geopolitics, crypto prices, sports, awards, and viral news. Liquidity is concentrated on flagship contracts (eg. US elections, major sports finals) and thin on long-tail markets. Resolution disputes are handled by UMA token holders, not a regulator. ## Which one should you use If you are a US retail trader who wants regulated event contracts inside an app you already use, Robinhood is the simplest path. If you want the widest catalog, non-custodial settlement, and you are outside the US (or already comfortable with self-custody), Polymarket has more depth. Either way, check the live status pages before funding or closing a position — both platforms have had outages during high-volume events. ## Frequently asked **Q: Is the Robinhood prediction market the same as Kalshi?** A: Functionally yes for many contracts — Robinhood routes event-contract trades to a CFTC-regulated exchange (Kalshi) and adds its own per-contract fee. You're trading the same underlying market through a different front end. **Q: Can US users access Polymarket?** A: Not officially. Polymarket geoblocks US IPs and does not onboard US persons after its 2022 CFTC settlement. Robinhood's event contracts are the regulated US-available alternative. **Q: Which has lower fees, Robinhood or Polymarket?** A: Polymarket has lower headline trading fees (often 0%), but you pay on the USD-to-USDC ramp. Robinhood charges a per-contract fee but free ACH funding. For small US-based traders, Robinhood is usually cheaper end-to-end. **Q: Are Robinhood event contracts gambling?** A: Legally no — they're regulated derivatives (event contracts) under the CFTC, not gambling under state law. Economically the mechanics resemble binary options. --- # Lesson 09 — The Best Prediction Markets in 2026 (Ranked & Compared) Module: Platforms URL: https://polymarket.health/learn/best-prediction-markets-2026 Published: 2026-02-01 Reading time: 8 min > Our 2026 ranking of the best prediction markets — Polymarket, Kalshi, PredictIt, Manifold and more — by liquidity, regulation, fees, and contract variety. There is no single "best" prediction market. There's the best one for your jurisdiction, your trading style, and the contracts you care about. Here's how the major platforms rank in 2026. ## 1. Polymarket — highest liquidity, crypto-native If you're outside the US, want the deepest order books on political and pop-culture markets, and are comfortable with USDC, Polymarket is the default. Fees are zero on trades; the platform makes money via spread. ## 2. Kalshi — best for US users Kalshi is the only fully-regulated, ACH-funded prediction market available to US users in all 50 states. Liquidity is concentrated on its top contracts; the deposit experience is the smoothest of any platform. ## 3. PredictIt — niche academic political PredictIt has lower liquidity and tight position limits, but its longevity and academic focus make it a useful data source for political markets. Best for small traders and researchers. ## 4. Manifold — best play-money platform Manifold isn't real money, but its market creation flexibility makes it the best place to test forecasting skills, run group prediction games, and learn the mechanics with no financial risk. ## 5. Crypto perp platforms (Drift, dYdX, Hyperliquid) Not prediction markets in the strict sense, but adjacent — they let you take leveraged directional positions on crypto and macro outcomes. Useful for users already comfortable with on-chain derivatives. ## Frequently asked **Q: Which prediction market has the lowest fees?** A: Polymarket charges zero trading fees but has a spread. Kalshi's fee schedule is published per contract and is usually 1–7% of profit. **Q: Can I use multiple prediction markets at once?** A: Yes — and many serious traders do, to arbitrage price differences between regulated and crypto markets. --- # Lesson 10 — Are Prediction Markets Legal in the US? (2026 Update) Module: Regulation & Risk URL: https://polymarket.health/learn/are-prediction-markets-legal-in-the-us Published: 2026-01-15 Reading time: 7 min > A clear, current breakdown of which prediction markets are legal where in the United States — Kalshi, Polymarket, PredictIt, Manifold, and offshore alternatives. The legal status of prediction markets in the United States changed dramatically between 2022 and 2025. This article reflects the situation as of 2026 — but always verify with the platforms themselves before depositing. ## Kalshi: fully legal Kalshi is regulated by the Commodity Futures Trading Commission (CFTC) as a Designated Contract Market. After winning a federal court ruling in 2024 that affirmed its right to offer election contracts, Kalshi now operates legally in all 50 states. ## Polymarket: blocked in the US Polymarket settled with the CFTC in January 2022 over operating an unregistered binary options market. It now geoblocks US IP addresses and requires geographic attestation. Using a VPN to access Polymarket from the US violates the platform's terms. ## PredictIt: academic exemption PredictIt operated under a CFTC no-action letter granted to Victoria University of Wellington. The no-action letter has been challenged and amended multiple times; PredictIt's continued operation has been preserved through litigation. Position limits are strict. ## Manifold and play-money platforms Manifold Markets uses Mana, a play-money currency, and is therefore not subject to gaming or derivatives regulation. It is legal everywhere. ## What about state-level laws? CFTC regulation generally preempts state gambling laws for federally-approved contracts. However, sports contracts have triggered pushback from individual state gaming regulators. The legal landscape for sports event contracts specifically is still evolving. ## Frequently asked **Q: Is it illegal for me to use Polymarket from the US?** A: Polymarket itself is not licensed to serve US customers, and using it from the US violates the platform's terms. There is no federal statute criminalizing the user, but accounts can be frozen. **Q: Will Polymarket return to the US?** A: As of 2026, Polymarket has signaled intent to seek US authorization but has not announced a timeline. --- # Lesson 11 — How to Read a Status Page (Without Being Misled) Module: Regulation & Risk URL: https://polymarket.health/learn/how-to-read-a-status-page Published: 2026-01-18 Reading time: 5 min > Status pages are marketing surfaces as much as engineering tools. Here's how to tell whether a platform is actually working. Status pages were invented by Atlassian's Statuspage product in the mid-2010s. Today every serious platform has one — but they vary wildly in honesty. ## What 'all systems operational' actually means A green badge means the platform's automated monitoring isn't tripping any alarms. It does not mean every user is having a working experience. If you're sure the platform is broken but the status page is green, you're probably not alone — there's often a lag of 10–30 minutes before an incident is acknowledged. ## Reading uptime numbers Monthly uptime of 99.9% sounds great until you realize it allows 43 minutes of downtime per month — usually concentrated during peak load. For prediction markets, that peak is exactly when you want to trade: election nights, Fed announcements, major sporting events. ## Incident history is the real signal Scroll past the green badge and read the incident history. Look for: frequency, average time to acknowledge, average time to resolve, and whether the same component fails repeatedly. A platform that posts post-mortems is signaling that it takes reliability seriously. ## Frequently asked **Q: Why is the status page green when the site is down?** A: Status pages update manually or on a delay. If many users are reporting an issue but the page is green, the incident hasn't been acknowledged yet. --- # Lesson 12 — Polymarket Outage History: Notable Incidents & Lessons Module: Regulation & Risk URL: https://polymarket.health/learn/polymarket-outage-history Published: 2026-01-22 Reading time: 6 min > A timeline of Polymarket's biggest outages, what caused them, and how to protect yourself when the platform goes down at the worst moment. Polymarket maintains 99.9%+ uptime in the aggregate, but the incidents that have happened — especially during the 2024 US election — illustrate the platform's structural weak points. ## Election night 2024 On the evening of November 5, 2024, Polymarket experienced multiple degradations as US election results came in. Order book latency spiked, the front-end loaded slowly, and some users reported failed wallet connections. The platform stayed online but its largest day of volume was its most stressed. ## RPC provider incidents Several Polymarket slowdowns have been caused by Polygon RPC degradation upstream — Alchemy, Infura, or QuickNode having issues simultaneously affects every Polygon front-end. These incidents are often resolved by the RPC providers within minutes but can stretch to hours. ## UMA resolution controversies Several markets have been disputed at the UMA oracle stage — the Ukraine/Zelensky suit market in early 2025 is the most cited example. These aren't outages in the uptime sense, but they're failures of the platform's information layer. ## Protecting yourself If you're trading on a high-volume night, place orders early, use limit orders rather than market orders, keep some MATIC for gas, and have a wallet you can sign with off-platform. When the front-end fails, your positions are still safe on-chain. ## Frequently asked **Q: Has Polymarket ever lost user funds?** A: No — because Polymarket is non-custodial, USDC stays in user wallets or on-chain market contracts. There has never been an exchange-style theft of customer balances. --- # Lesson 13 — Prediction Market Glossary: 30+ Terms Every Trader Should Know Module: Reference URL: https://polymarket.health/learn/prediction-market-glossary Published: 2026-01-25 Reading time: 9 min > The complete glossary of prediction-market terminology — from order books and oracles to UMA, CFTC, no-action letters, and event contracts. If you're new to prediction markets, the vocabulary can be a barrier — every market borrows terminology from securities trading, crypto, and regulatory law. This glossary covers everything you'll see. ## Trading terms Binary contract: A contract that pays $1 if an event happens and $0 if it doesn't. Order book: The list of buy and sell orders for a market. Spread: The difference between the best bid and ask. Slippage: The price movement that happens between when you click and when your order fills. Market maker: A trader (or algorithm) that posts both bids and asks to provide liquidity. ## Crypto terms USDC: A US-dollar-pegged stablecoin issued by Circle, used as the unit of account on Polymarket. Gas: The fee paid in the chain's native token (MATIC on Polygon) to process a transaction. Wallet: Software that holds your private key and signs transactions. MetaMask, Rabby, and Polymarket's embedded wallet are common choices. Bridging: Moving funds from one chain to another. ## Oracle and resolution Oracle: A system that brings real-world data on-chain. UMA: The optimistic oracle Polymarket uses to resolve markets. Dispute: A formal challenge to a proposed outcome; resolved by UMA token holders. Settlement: Paying out winners after a market resolves. ## Regulatory terms CFTC: Commodity Futures Trading Commission, the US regulator for derivatives. Event contract: A binary contract on a real-world event, as defined by the CFTC. DCM: Designated Contract Market, the CFTC license category Kalshi holds. No-action letter: A formal statement from the CFTC that it will not pursue enforcement against a specific activity (PredictIt's basis for operating). Geoblocking: Restricting access based on user location. ## Frequently asked **Q: What's the difference between a prediction market and a sportsbook?** A: Sportsbooks set odds and take the other side of every bet. Prediction markets match users against each other; the platform takes a fee but no directional exposure. ---