Best Prediction Market Platforms in 2026: Polymarket, Kalshi, ForecastEx and More
Answer first
The best prediction market platform depends first on which venue and contract you are legally eligible to use. Polymarket's international protocol, Polymarket US, Kalshi, and ForecastEx through Interactive Brokers are different products with different rules and access. After eligibility, compare the exact contract wording, resolution source, order book, spread, fee, funding path, custody, and exit liquidity.
Polymarket is a strong research fit for users who want a broad international crypto-native market and can work with its rule and oracle model where eligible. Kalshi is a strong fit for users who want event contracts on a designated contract market and can use the specific contract in their jurisdiction. ForecastEx is a strong fit for eligible Interactive Brokers clients who want event contracts inside a brokerage workflow, especially around published economic or climate outcomes.
Token Metrics ranked scorecards
Polymarket
Best for: Eligible international-protocol users who inspect each market's rules and live book.
Watch: Geographic access, custody, and executable depth remain market- and user-specific.
Score scope: This 74 score is for the Polymarket International protocol only. Polymarket US is a separate venue with separate rules, access, and evidence and is not scored in this card.
Score breakdown
Overall rationale: Polymarket ranks first on category-relative product quality because the reviewed first-party evidence supports strong contract-resolution mechanics, execution controls, fee disclosure, market structure, and decision tools. International access remains a separate hard gate and does not add or subtract product-quality points.
Score confidence: Independent audit complete. 6 of 6 required factors have scoreable evidence.
User eligibility: Verify international-protocol access. Confirm the current location, wallet, collateral, exact market, and protocol access without using Polymarket US evidence.
- Contract Resolution Quality80/100 × 25%
-
The international protocol documents predefined rules, UMA optimistic-oracle resolution, a two-hour challenge period, and a multi-day dispute path. The score is below 100 because the exact market rules remain contract-specific.
First-party evidence: Polymarket Resolution
- Execution Liquidity75/100 × 25%
-
First-party documentation exposes order-book bids and asks, spread, liquidity, volume, market status, minimum order size, market orders, limit orders, partial fills, and order-state behavior. It does not establish that every live market has deep executable depth.
First-party evidence: Polymarket Place Orders, Polymarket Market Details
- Fees Total Cost75/100 × 15%
-
Polymarket documents zero maker fees, category- and probability-dependent taker fees, fee-free geopolitics/world-events markets, and possible intermediary costs. Exact costs remain market-specific.
First-party evidence: Polymarket Fees
- Market Breadth Relevance70/100 × 10%
-
The platform supports binary markets, grouped multi-market events, negative-risk groups, and multiple topic structures. The score is not higher because the cited documentation does not provide a complete current breadth inventory.
First-party evidence: Polymarket Markets and Events
- Funding Custody Settlement45/100 × 10%
-
The protocol documents pUSD collateral and new exchange infrastructure, but the evaluated evidence does not fully establish user funding, withdrawal, custody, or recovery protections.
First-party evidence: Polymarket V2 Migration
- Tools Decision Support85/100 × 15%
-
First-party materials document GTC and GTD limit orders, market orders, FAK/FOK behavior, minimum sizes, price increments, market-state checks, APIs, and order/trade identifiers.
First-party evidence: Polymarket Place Orders, Polymarket Market Details
Arithmetic: 80×25% + 75×25% + 75×15% + 70×10% + 45×10% + 85×15% = 74.25; ROUND_HALF_UP = 74.
ForecastEx
Best for: Eligible IBKR clients researching published-outcome contracts.
Watch: Execution depth and account eligibility remain contract-specific.
Score breakdown
Overall rationale: ForecastEx via IBKR ranks second on category-relative product quality, with strong documented contract and settlement mechanics, transparent per-contract fees, collateral structure, and brokerage tools. Current user and contract eligibility remains a separate hard gate.
Score confidence: Independent audit complete. 6 of 6 required factors have scoreable evidence.
User eligibility: Verify current access. Confirm the IBKR affiliate, age, residence, account, exact exchange, and contract eligibility before trading.
- Contract Resolution Quality85/100 × 25%
-
ForecastEx first-party FAQ explains Yes/No selection, $1/$0 settlement, published-outcome sourcing, contract expiration, and contract-specific research. The exact source, threshold, period, correction rule, and settlement terms still require per-contract review.
First-party evidence: ForecastEx Frequently Asked Questions, Economic Forecast Contracts from ForecastEx
- Execution Liquidity55/100 × 25%
-
The live IBKR prediction-market interface exposes current contract listings, prices, displayed liquidity comparisons, categories, and closing times, while IBKR describes comparison across ForecastEx, Kalshi, and CME. The evidence does not establish consistently deep executable depth or narrow spreads for every ForecastEx contract.
First-party evidence: IBKR Prediction Markets App
- Fees Total Cost85/100 × 15%
-
ForecastEx publishes a one-cent-per-contract transaction fee charged to each side, while IBKR's direct-client schedule lists no IBKR commission plus a one-cent exchange fee for ForecastEx. Introduced or advised accounts may differ, so the in-app quote remains controlling.
First-party evidence: ForecastEx Frequently Asked Questions, Interactive Brokers Prediction Market Commissions
- Market Breadth Relevance65/100 × 10%
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ForecastEx and IBKR document economic, elections, government, climate, financial, and environmental contract categories, with the live interface showing current examples. The score does not assume that all categories or contracts are available to every account.
First-party evidence: ForecastEx Frequently Asked Questions, IBKR Prediction Markets App
- Funding Custody Settlement80/100 × 10%
-
ForecastEx states that contracts are fully collateralized, cash is deposited by the member before bids are accepted, and ForecastEx is the exchange and clearinghouse. This supports a high score, while the user still depends on an eligible FCM and broker account.
First-party evidence: ForecastEx Frequently Asked Questions, IBKR Prediction Markets
- Tools Decision Support75/100 × 15%
-
IBKR documents staged ScaleTrader orders for ForecastEx, unified venue comparison, contract search, category navigation, and displayed market information. Staged orders can partially fill, and cross-venue comparison is valid only when contract rules are identical.
First-party evidence: Using ScaleTrader for ForecastEx Contracts, IBKR Prediction Markets App, IBKR Prediction Markets
Arithmetic: 85×25% + 55×25% + 85×15% + 65×10% + 80×10% + 75×15% = 73.50; ROUND_HALF_UP = 74.
Kalshi
Best for: Eligible users who prefer a US designated contract market.
Watch: Check user, state, account, contract, funding, and live depth before trading.
Score breakdown
Overall rationale: Kalshi ranks third on category-relative product quality in this reviewed cohort. First-party evidence supports its exchange workflow, contract access, order controls, fee schedule, and market breadth; current user and contract eligibility remains a separate hard gate.
Score confidence: Independent audit complete. 6 of 6 required factors have scoreable evidence.
User eligibility: Verify current access. Confirm country, state, age, identity, account, payment, and exact contract access before trading.
- Contract Resolution Quality75/100 × 25%
-
The product certification demonstrates contract-specific definitions, source language, trading conditions, and settlement procedures. The evidence does not prove identical rules for every market.
First-party evidence: Kalshi CONTROL Product Certification
- Execution Liquidity70/100 × 25%
-
Kalshi documents a matching order book, makers and takers, market makers, limit-order price control, partial fills, and the possibility of unfilled orders. It does not provide a single universal current spread/depth statistic, so the score is below 80.
First-party evidence: Kalshi Limit Orders, Who Are You Trading With on Kalshi?
- Fees Total Cost75/100 × 15%
-
Kalshi explains expected-earnings transaction fees, market-specific fees, maker fees, fee-free cancellation of resting orders, and order-level fee visibility. Exact costs remain contract- and execution-specific.
First-party evidence: Kalshi Fees, Kalshi Limit Orders
- Market Breadth Relevance80/100 × 10%
-
First-party material demonstrates use cases spanning directional trading and hedging across inflation, interest-rate, hurricane, and other event risks. This is category coverage evidence, not a popularity or volume score.
First-party evidence: Who Are You Trading With on Kalshi?, How Is Kalshi Regulated?
- Funding Custody Settlement55/100 × 10%
-
Regulated DCM status and contract settlement documentation support institutional structure, but the cited evidence does not fully document the user's funding, withdrawal, or custody workflow.
First-party evidence: How Is Kalshi Regulated?, Kalshi CONTROL Product Certification
- Tools Decision Support75/100 × 15%
-
Kalshi documents limit orders, precise price control, quantity requirements, partial fills, maker/taker behavior, and the trade-off between execution certainty and price control.
First-party evidence: Kalshi Limit Orders
Arithmetic: 75×25% + 70×25% + 75×15% + 80×10% + 55×10% + 75×15% = 72.25; ROUND_HALF_UP = 72.
How scoring works: These category-relative scores use continuous 0-100 factor values and audited vertical weights. Missing evidence is recorded as unknown and blocks score publication; it is never converted into numeric product weakness. Evidence confidence and current user eligibility remain separate from the product score. Read the v2 methodology.
Decision table
| Decision | Practical guidance | What to verify |
|---|---|---|
| Crypto-native international protocol | Polymarket international may fit eligible users who understand wallet funding and oracle-based resolution. | Check current geographic restrictions, the exact venue, fee category, order book, collateral path, and market rules. [9] [1] [2] |
| US designated contract market | Compare Polymarket US and Kalshi only at the contract and account level. | Confirm which DCM lists the contract, user eligibility, funding, fee display, rulebook, and settlement source. [3] [10] [4] [5] |
| Brokerage event-contract access | ForecastEx may fit eligible IBKR clients who want event contracts beside other brokerage tools. | Confirm client eligibility, affiliate, contract venue, fee-inclusive quote, market hours, and the current schedule. [7] [8] |
| Same topic on several platforms | Do not assume the contracts are fungible because the headlines look alike. | Compare wording, definitions, cutoff, source hierarchy, void rules, settlement time, price, depth, and all costs. |
Best for and avoid if
Best for
- Readers who will check eligibility and the exact contract before comparing a displayed probability.
- Traders who understand that a winning view can still lose after spread, fees, poor entry, or an unfavorable rule interpretation.
- Users willing to keep international protocol products, US designated contract markets, and broker-distributed contracts separate.
Avoid if
- You want one access statement to cover every country, state, app, venue, and contract family.
- You will trade from the market title without reading definitions, sources, deadlines, and settlement procedures.
- You cannot tolerate a total loss of the contract price, disputed resolution, thin exits, or changing legal access.
Start with venue identity
A platform name can hide more than one legal and technical venue. Polymarket's international documentation describes a protocol with an order book, USDC-related flows, and UMA resolution. A separate CFTC listing identifies QCX LLC doing business as Polymarket US as a designated contract market. Those facts must not be merged into a claim that every Polymarket contract follows the same US rules.
Kalshi describes itself as a CFTC-regulated designated contract market. ForecastEx contracts are distributed through Interactive Brokers alongside other event-contract venues. Record the exchange, distributor, product, and contract family in every comparison. The app used to reach a contract may not be the exchange that defines its rules and settlement.
Polymarket international
Polymarket's international documentation says market prices are traded through an order-book system and that predefined rules name the resolution source and end date. Its resolution page describes the UMA Optimistic Oracle and a challenge and dispute process. Winning tokens redeem for one dollar after resolution, while losing tokens become worthless. Read the rules, not only the question in the title.
The fee page says taker fees vary by category and probability, makers are not charged, and geopolitics or world-events markets are fee-free. It also says Polymarket does not charge for USDC deposits or withdrawals, while intermediaries may. Verify the current market's fee display because the category and price affect cost.
Polymarket US
The CFTC's trading-organization list identifies Polymarket US as a designated contract market. A reviewed contract filing describes one-dollar event contracts, full at-risk collateral, source hierarchies, settlement procedures, and participant restrictions for a specific athletic tie contract family. That filing is useful evidence about that family, not permission to generalize every rule to every Polymarket US market.
A US user should verify that the account and exact contract belong to the US venue, then read the current product terms and rule filing. Do not use international protocol documentation to fill gaps in a US contract. The names may be related, but collateral, fees, resolution, access, and legal treatment can differ.
Kalshi
Kalshi's current help material says it is a CFTC-regulated designated contract market. Its official product certifications show contract prices between one cent and ninety-nine cents for one-dollar notional outcomes and refer to exchange rules, fees, and settlement conditions. The current site displays markets across several event categories, but availability still depends on user and contract eligibility.
Kalshi says transaction fees are based on expected earnings and that some markets can also have maker fees. That means one universal percentage is misleading. Inspect the fee shown for the exact order. Kalshi also says international access exists in many countries subject to identity, residency, member-agreement, local, and payment restrictions. Verify current eligibility before funding.
ForecastEx through Interactive Brokers
Interactive Brokers says eligible clients can access event contracts from ForecastEx, Kalshi, and CME within one interface. Its ForecastEx education focuses on contracts tied to published economic and climate outcomes and explains that event contracts typically settle at zero or one dollar. The broker's product can be attractive when a user wants an event contract inside an existing account workflow.
Eligibility varies by affiliate, country, age, and contract. IBKR says eligible prediction-market clients must be at least twenty-one and notes specific limits for ForecastEx election contracts. Its current direct-client schedule lists no IBKR commission plus a one-cent exchange fee for ForecastEx, but programs and introduced or advised accounts can differ. Verify the fee-inclusive quote in-app.
Liquidity and spreads
A probability-like price is only as useful as the order book behind it. Inspect the best bid, best offer, spread, available size, recent trading, and depth near the intended order. A market with a compelling headline can still be expensive to enter or impossible to exit at the displayed price. A small last trade does not prove that a larger order will fill there.
Compare identical economic exposure, not only similar topics. When two contracts use different deadlines or sources, price differences may reflect rules rather than an arbitrage. For a genuine comparison, calculate the net payout after entry price, fees, spread, and exit or settlement cost. Use limit orders when appropriate, but remember that a limit may never fill.
Resolution rules are the product
Read definitions for the event, outcome, time zone, cutoff, official source, correction policy, and settlement process. Look for what happens when data is delayed, revised, ambiguous, or unavailable. A market can settle against a defined source even when another reputable source reports a different number. The title is a summary, not the full contract.
Polymarket international explicitly tells users that the rules define resolution and describes an oracle dispute path. US DCM filings can contain source hierarchies and contract-specific procedures. Kalshi product filings tie contracts to exchange rules. ForecastEx educational material ties many contracts to published indicators. These systems differ, but the user control is the same: read before trading.
Fees and total cost
Polymarket publishes category and probability-dependent taker fees for certain markets and says makers are not charged. Kalshi says fees depend on expected earnings and can include maker fees in some markets. IBKR publishes a per-contract schedule that varies by exchange and account program. These structures cannot be reduced to one headline rate without losing material detail.
Price the actual order. Include platform or exchange fee, broker commission, spread, funding cost, payment or conversion fee, blockchain fee where relevant, withdrawal or intermediary cost, and the cost of closing early. When a primary source or live quote does not settle the question, say to verify it in-app. Never invent a fee to complete a table.
Funding, custody, and settlement
Polymarket international uses a crypto-native flow documented around USDC and wallet-based trading. US DCM and brokerage products may use different collateral and account systems. Identify the asset or currency deposited, who holds it, whether funds are segregated or fully collateralized under the contract rules, how withdrawals work, and what happens after settlement.
A one-dollar winning payout is not a one-dollar profit. Profit depends on entry price and all costs. Closing before settlement adds a new trade and spread. Holding through settlement adds rule, timing, and operational exposure. Keep position size within an amount that can be lost entirely without forcing another portfolio decision.
Final platform fit
Use Polymarket international when eligible and when its market breadth, order book, wallet flow, and oracle rules fit the contract you want. Use Polymarket US only for a contract actually listed on that venue and under its own rules. Use Kalshi when its DCM structure, market, account access, and in-app fee fit. Use ForecastEx when IBKR eligibility, brokerage access, and the published-indicator contract fit.
Use no platform when the jurisdiction, venue, contract wording, source, fee, funding, or exit cannot be explained. A high-volume category does not require participation. The best decision page should make refusal easy when the contract is not clear enough to price.
A contract comparison worksheet
Begin with a plain-language row for each contract. Record the platform name, exchange entity, distributor, account type, user jurisdiction, contract identifier, yes and no definitions, exclusions, time zone, deadline, official source, correction rule, void rule, trading cutoff, settlement path, and dispute process. If the same field has a different answer on two platforms, the contracts are not interchangeable even when their titles look alike.
Add an execution row captured at the same time. Record best bid, best offer, spread, size at both prices, deeper book levels, intended quantity, estimated average fill, exchange or protocol fee, broker commission, funding cost, crypto conversion or network cost, and a realistic early-exit quote. Keep unknown values as unknown. Do not use a zero merely because a charge was not visible in a comparison article.
Add a payoff row. For each possible settlement, calculate cash returned, entry cost, fees, and net result. Include a delayed-settlement case and an early-exit case. This exposes contracts where a small apparent price difference is smaller than the spread or fee. It also shows when a hedge is only loosely connected to the user's real exposure.
Finally add a source-quality row. Give current governing rules and official fee or eligibility pages the highest weight. Keep first-party product claims scoped to their venue. Attribute industry reporting and timestamp it. If the worksheet depends on a current fact that the approved source set cannot prove, the decision is verify in-app or no-platform, not an estimated answer.
Keep a final decision row with pass, wait, reject, and the reason. A pass means the venue and contract are understood, not that the selected outcome is likely. A wait names the missing document, price, or eligibility fact and a recheck time. A reject preserves the rule, cost, liquidity, or account boundary that failed so the same weak setup is not reopened by a later headline.
Review the worksheet again after settlement or exit. Compare the official source and actual fee with the assumptions saved at entry. Record delays, clarifications, partial fills, and any difference between the expected and realized route. This post-trade check evaluates the process without turning one winning side into evidence that the platform or strategy is generally superior.
Decision checklist
- Name the venue: Record exchange, distributor, app, jurisdiction, and contract family without merging related brands.
- Verify eligibility: Check user, country, state, age, residency, account, and contract restrictions now.
- Read the full rules: Resolve definitions, source hierarchy, cutoff, time zone, correction policy, void terms, and settlement path.
- Inspect the book: Compare bid, offer, spread, depth, recent activity, and full-size fill rather than the last price.
- Calculate total cost: Include fees, commissions, spread, funding, conversion, network, withdrawal, and early-exit cost.
- Confirm custody: Know the collateral, account holder, withdrawal process, and post-settlement flow.
- Set maximum loss: Size for a zero payout and do not rely on closing liquidity to prevent the loss.
Risk review
| Risk | Why it matters | Control |
|---|---|---|
| Venue confusion | International, US DCM, and broker-distributed products can share brands or topics. | Record the exact exchange and contract rules before comparing. [3] [7] |
| Resolution mismatch | A common-language interpretation can differ from the contract's defined source and deadline. | Read the rules and source hierarchy before trading. [2] [10] |
| Access change | Country, state, account, and contract eligibility can change or differ. | Verify current access on the official product and applicable terms. [9] [6] |
| Thin liquidity | The displayed probability may not be available for the intended size or exit. | Inspect spread and depth, use a limit where appropriate, and size for no early exit. |
| Fee complexity | Category, probability, expected earnings, exchange, and account program can change cost. | Use the exact in-app fee preview and current primary schedule. [1] [5] [8] |
These controls reduce avoidable errors. They do not remove market, contract, custody, or legal risk.
How this page was evaluated
The scorecard uses the category-relative v2 continuous 0-100 model, calibrated August 25, 2026. Each required factor receives an evidence-backed score across the full range, then its audited vertical weight is applied. Missing evidence is stored as unknown and blocks publication of the overall category score; it never becomes numeric product weakness. Score confidence and current user eligibility are reported separately. Use the methodology link above for the full rubric. A category score is a decision aid, not universal user suitability or a promise of profit or platform safety. We recheck volatile product, fee, access, and rule facts against the cited pages before release.
| Criterion | Weight |
|---|---|
| Contract Resolution Quality | 25 |
| Execution Liquidity | 25 |
| Fees Total Cost | 15 |
| Market Breadth Relevance | 10 |
| Funding Custody Settlement | 10 |
| Tools Decision Support | 15 |
Frequently asked questions
What is the best prediction market platform in 2026?
The best fit depends first on legal and geographic eligibility, then on the exact contract, liquidity, rules, costs, funding, and tools. Compare Polymarket international, Polymarket US, Kalshi, and ForecastEx as separate venues or products.
Are Polymarket international and Polymarket US the same venue?
No. International protocol documentation and the CFTC-listed US designated contract market must be evaluated separately. Do not apply one venue's rules or access statement to the other. [2] [3]
Which platform has the lowest fees?
There is no universal answer. Polymarket, Kalshi, and IBKR use different fee structures that can vary by market, probability, expected earnings, exchange, and account program. Verify the current order quote. [1] [5] [8]
Can a prediction market contract lose its full value?
Yes. A losing one-dollar binary contract can settle at zero, so the amount paid for it can be lost. Spread, fees, and funding costs can add to the economic loss. [2] [10]
Sources checked
- Polymarket FeesScope: Polymarket says makers are not charged fees, taker fees vary by category and probability, and geopolitics or world-events markets are fee-free. Deposit or withdrawal intermediaries may still charge. Caveat: Fee parameters can change by market. Keep international protocol fees separate from Polymarket US products and verify the current order quote.
- Polymarket ResolutionScope: Polymarket's international protocol documentation says markets use predefined resolution rules and UMA's optimistic oracle, with a two-hour challenge period and a dispute path that can take four to six days. Caveat: These mechanics apply to the international protocol documentation. Do not apply them to Polymarket US DCM contracts without contract-specific proof.
- CFTC Trading Organizations: Designated Contract MarketsScope: The CFTC lists QCX LLC doing business as Polymarket US as a designated contract market, designated July 9, 2025. Caveat: The designation does not make every international Polymarket market a CFTC-regulated US contract or prove universal user access.
- How Is Kalshi Regulated?Scope: Kalshi says it is a CFTC-regulated designated contract market, and the CFTC DCM list independently confirms Kalshi's designation. Caveat: DCM status does not remove contract-specific, state, age, eligibility, litigation, liquidity, or loss risk.
- Kalshi FeesScope: Kalshi says transaction fees depend on expected earnings and that some markets can also have maker fees, with the applicable fee displayed in the product and current schedule. Caveat: Do not reduce Kalshi fees to one universal percentage. Verify the exact market, side, size, account, and current in-app quote.
- Can I Trade on Kalshi from Outside the United States?Scope: Kalshi says it is available in many countries subject to its member agreement, identity verification, residency, local restrictions, and differing payment options. Caveat: Broad availability language does not prove that every country, payment rail, account, or contract is eligible. Verify current access in-app.
- IBKR Prediction MarketsScope: Interactive Brokers provides one interface for event contracts from Kalshi, ForecastEx, and CME, says eligible clients must be at least 21, and limits ForecastEx election contracts to eligible US residents. Caveat: Eligibility varies by affiliate, country, account, and contract. A broker interface does not make every listed contract a ForecastEx product.
- Interactive Brokers Prediction Market CommissionsScope: IBKR's direct-client schedule lists no IBKR commission plus a one-cent exchange fee for ForecastEx contracts, and one-cent IBKR commission plus a one-cent exchange fee for Kalshi and CME contracts. Caveat: Rates can change and introduced or advised accounts may pay more. Verify the exact fee-inclusive in-app quote.
- Polymarket Geographic RestrictionsScope: Polymarket publishes geographic restrictions for access to its international product and instructs users to follow applicable location rules. Caveat: Restrictions can change and public market data does not prove trading eligibility. Verify actual current location and product access without using a workaround.
- Polymarket US Athletic Tie Contract FilingScope: The filing describes one Polymarket US athletic tie contract family with $1 contracts, full at-risk collateral, official source hierarchies, settlement procedures, and participant restrictions. Caveat: This filing concerns a specific contract family. Do not generalize its source, restriction, or settlement language to every Polymarket US product.
- Kalshi CONTROL Product CertificationScope: The product certification illustrates that Kalshi contracts use contract-specific definitions, source language, trading conditions, and settlement procedures. Caveat: This filing is evidence for its own contract family, not a universal description of every Kalshi market. Read the exact contract rules.
- Economic Forecast Contracts from ForecastExScope: IBKR course material describes ForecastEx contracts designed around published economic, financial, and climate outcomes and their settlement research workflow. Caveat: Course material is educational and contracts vary. Read the current named source, period, threshold, correction rule, and settlement terms.
