Kalshi vs Polymarket: What’s the Difference?
Same headline, different market. Here’s why these two major prediction platforms sometimes disagree — and what that means before you place a trade.
New to prediction markets? Here's what you're actually looking at.
Kalshi: US-only, verified accounts, regulated by CFTC as a DCM. Polymarket: international crypto traders (no US retail via QCX LLC rules). This matters when you're interpreting a spread — the two price feeds come from different populations.
Kalshi caps positions at $25K on most political contracts. Polymarket has higher limits — we flag concentrated positioning with a CONCENTRATED badge when top positions exceed 30% of volume.
Political markets resolve on a specific public trigger: AP call, electoral certification, or CFTC-designated source. The rule is fixed when the market opens. It is NOT 'who the media thinks won' — the resolution rule is the only thing that matters.
These markets exist to aggregate public forecasts, not to profit from outcomes. No one 'wins' because a policy goes badly — they win because they correctly read the consensus before it shifted.
Kalshi
The regulated U.S. exchange
Polymarket
The broader global venue
Key Differences
Five places where Kalshi and Polymarket take meaningfully different approaches.
Settlement Philosophy
Rule-based resolution inside a regulated exchange structure.
Resolution depends on the specific Polymarket venue and its published rules.
Market Focus
U.S.-regulated event contracts across headline-driven categories.
U.S. regulated venue plus a separate international product with broader coverage.
Volume
Activity is highly event-driven.
Activity is also event-driven and split across U.S. and international venues.
User Experience
USD-native onboarding with a more traditional exchange feel.
Different onboarding paths depending on whether you use the U.S. venue or the international product.
Fee Structure
Published formula-based fee: up to 1.75¢/contract at 50¢ odds, less for longshots/favorites. Entry only — exiting is free. Politics/policy markets are free. In plain English: the closer to a coin flip, the more you pay, but it maxes out at under 2 cents.
Fee structure updated March 30, 2026. Geopolitics/world events: $0. Sports: up to ~0.75% at 50¢; Crypto: up to ~1.80% at 50¢; Politics/Finance/Tech: up to 1.00%. On Polymarket US (regulated venue): probability-based taker fee peaking at 0.75% peak for sports. Limit order makers get rebates, never pay fees.
Fee Breakdown: What You Actually Pay
The fee structures in plain English, with concrete examples.
Kalshi
Formula: 0.07 × P × (1 − P) per contract
Kalshi's fee scales with uncertainty. At 50/50 odds, you pay the max — 1.75¢ per contract. At 80¢, it's about 1.12¢. At 10¢, it's about 0.63¢. At 95¢, it's about 0.33¢.
Dollar example: Buy 100 contracts at 50¢ = $1.75 total in fees. Entry only — selling or exiting is free. Politics and policy markets: zero fees.
Polymarket
Geopolitics/world events: $0. Sports: up to 0.75% at 50¢. Crypto: up to 1.80% at 50¢. Politics/Finance/Tech: up to 1.00%.
As of March 30, 2026, geopolitics and world events remain free. Sports can run up to 0.75% at 50¢ at 50/50 odds, and crypto can run up to 1.80% at 50¢.
Polymarket US venue (CFTC-regulated): Flat 0.75% peak taker fee — 30 cents per $100 traded. Place a limit order instead and you get 20 cents back per $100.
Resolution Sources by Category
How each platform settles markets depends on the category. Compare settlement sources, timing, and gap risk.
politics
Kalshi
Source
Official government sources (AP, official canvass)
Timing
Can resolve same-night on AP race call — often fastest for elections.
Rule
Resolves based on AP race call or official certified result, whichever comes first.
Polymarket
Source
AP or official government declaration
Timing
UMA oracle resolution can take 24–72h; admin review possible in disputed outcomes.
Rule
Resolves based on AP call or official declaration. Admin review committee handles edge cases.
sports
Kalshi
Source
Official league/governing body results
Timing
Resolves within 48h of official league result.
Rule
Resolves YES if the specified team wins as confirmed by official results within 48 hours of event.
Polymarket
Source
UMA oracle / Polymarket resolution committee
Timing
UMA oracle + possible admin review. Usually same-day for major leagues.
Rule
Resolves YES if the specified team wins. Admin review possible if unusual circumstances occur.
finance
Kalshi
Source
Official exchange/index closing price
Timing
Resolves on official closing price — NOT intraday, NOT after-hours.
Rule
Resolves based on official closing price on the specified date.
Polymarket
Source
Yahoo Finance or WSJ Historical Prices (varies by market — check contract terms)
Timing
Resolves on official closing price — NOT intraday, NOT after-hours. UMA oracle review may add 24–48h.
Rule
Resolves based on official closing price from designated source. Range markets typically use Yahoo Finance; daily up/down markets typically use WSJ. Always check the specific market's resolution source.
economics
Kalshi
Source
Official government data releases (BLS, BEA, Fed)
Timing
Resolves on official data release date — NOT revised data, NOT estimates.
Rule
Resolves based on the official data release from the designated government agency.
Polymarket
Source
Official government data releases
Timing
Resolves on official data release. UMA oracle review may add 24–48h.
Rule
Resolves based on the official data release from the designated government agency.
weather
Kalshi
Source
NOAA weather station data (specific station varies by market)
Timing
Resolves at specific hourly reading at designated NOAA station — NOT peak, NOT forecast, NOT your local app.
Rule
Resolves based on hourly reading at designated NOAA station — NOT forecast, NOT peak, NOT your local temperature.
Polymarket
Source
Polymarket admin / UMA oracle
Timing
UMA oracle resolution; timing varies by market — check specific market page.
Rule
Resolution rule varies by market — check specific market page for source details.
crypto
Kalshi
Source
Binance/Coinbase closing or spot price
Timing
Resolves at specified exchange closing price — typically within minutes of expiry.
Rule
Resolves based on specified exchange price at market close date/time.
Polymarket
Source
CoinGecko / Binance spot price
Timing
Chainlink price feed; typically resolves within minutes of expiry.
Rule
Resolves at specified time using designated price feed.
When They Disagreed: Real Case Studies
This is not theoretical. Each case below shows a real market where Kalshi and Polymarket could reasonably end up with different outcomes.
Different rulebooks, different outcomes
2026Case-by-case volumeKalshi resolves markets under its own published specifications and exchange procedures.
Polymarket outcomes depend on the specific market's published resolution method.
Lesson: Do not assume two markets on the same headline will resolve identically across platforms.
Which One Should You Use?
Neither platform is better across the board. The right choice depends on what you value most: regulation, liquidity, market coverage, or simplicity.
Use Kalshi if…
- You are a US resident who wants straightforward regulation
- You prefer rule-based settlement with clear written criteria
- You want weather, economics, or US sports markets
- You want a mobile app experience
- You prefer depositing from a bank account or debit card
- You want CFTC DCM-level regulatory protection
Use Polymarket if…
- You want deep liquidity on sports markets (US) or global events (international)
- You trust community oracle voting for fair settlement
- You prefer fiat deposits (card, bank, Coinbase Pay) or direct USDC
- You want a platform with fewer active legal disputes
- You want to trade international events not available on Kalshi
- You value 24/7 trading and on-chain settlement transparency
Full Comparison Table
A side-by-side look at the features that matter most.
| Feature | Kalshi | Polymarket |
|---|---|---|
| Regulatory Status | CFTC DCM + DCO | CFTC DCM (Polymarket US) |
| Resolution Method | Exchange rules and published specifications | Venue-specific published procedures |
| Crypto Wallet Required | No | Depends on venue and funding path |
| Mobile App | App support available | App / web support depends on venue |
| US Access | Federally regulated, with some state disputes | Yes (via QCX LLC) |
| Minimum Trade | $1 | $1 |
| Deposit Methods | ACH, wire, debit card, crypto options documented by Kalshi | Varies by venue and current product flow |
| Market Categories | Broad regulated event categories | Broader internationally; narrower on the U.S. venue |
| Best For | Traditional finance users | Deep liquidity seekers; fiat and crypto users alike |
| Settlement Disputes | Some high-profile disputes have drawn scrutiny | Check venue-specific history and rules |
| API Access | REST API (free) | Gamma API (free) |
| Trading Fees | Formula-based: ≤1.75¢/contract (formula-based) (max at 50/50 odds). Free to exit. Politics/policy free. | Updated Mar 30 2026. Geopolitics $0. Sports up to 0.75% at 50¢; Crypto up to 1.80% at 50¢; Politics/Finance/Tech up to 1.00%. Polymarket US: 0.75% peak sports peak. |
| Founded | 2018 | 2020 |
| Headquarters | New York, NY | New York, NY |
Market Quality Context
Spread interpretation: The Polymarket market shows concentrated positioning (~18% in top positions). This can distort the price relative to real consensus.
Contract mismatch
AP calls a winner on election night. Federal certification happens weeks later — and can be contested.
Resolution: kalshi uses federal certification; polymarket uses AP call
See Live Prices on Both Platforms
Compare real-time Kalshi and Polymarket prices side by side. See where the platforms diverge before you assume a price gap means easy money.
See live cross-platform marketsFrequently Asked Questions
Is Kalshi or Polymarket bigger?
Volume is event-driven and changes constantly. Check live data if you need current numbers. In practice, strength varies by category, contract, and moment.
Why did Kalshi and Polymarket give different answers on the same event?
Because the contracts and resolution methods can differ. Kalshi resolves under its exchange rules and published specifications. Polymarket depends on the venue and that market's published resolution process. If the wording is ambiguous, the outcomes can diverge.
Can US residents use both Kalshi and Polymarket?
Both have U.S.-regulated paths, but availability can depend on the specific product and current legal posture. Check the live onboarding terms before assuming access.
Which platform is safer for my money?
Neither is FDIC-insured. Kalshi has the longer-established U.S. regulated exchange footprint; Polymarket also has a U.S. regulated venue through QCX LLC d/b/a Polymarket US. Read the current transfer, custody, and rule documents before funding either one.
Does one platform have consistently better prices?
No. Prices can diverge because the venues have different trader bases, liquidity, and sometimes different contract wording.
Should I use both platforms?
Many active traders do. Using both gives you broader market coverage, better price comparison, and a fallback if one platform lacks the market you want. The tradeoff is extra complexity: more accounts, more funding paths, and two different rulebooks.
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Cross-Platform MarketsKalshi Legal WarSettlement GuideArbitrage TrackerSources: CFTC regulatory filings, Kalshi and Polymarket public documentation, CFTC records, Reuters reporting on Polymarket's U.S. return, and other public platform materials. Last updated April 2026. PredictionMarkets.us is not affiliated with either Kalshi or Polymarket.