NFL: Kalshi vs Polymarket
Live event-contract pricing on the 3 contestants where both Kalshi and Polymarket have current quotes. Sorted by edge size — biggest mispricings first.
Trade on Kalshi →Trade on Polymarket →Sponsored · code BOOKISH on Kalshi · code SPORTSBOOKISH on Polymarket (iOS) · 18+
Buy on Kalshi (Polymarket prices it higher)
| Contestant | Event | Kalshi ↗ | Polymarket ↗ | Edge | Poly vol |
|---|---|---|---|---|---|
| Carolina | NFC Championship Winner | 2.0% | 100.0% | +97.95% | $2107k |
| Carolina | NFC South Division Winner | 22.0% | 94.0% | +72.00% | $2073k |
Sell on Kalshi (Polymarket prices it lower)
| Contestant | Event | Kalshi ↗ | Polymarket ↗ | Edge | Poly vol |
|---|---|---|---|---|---|
| Buffalo | AFC East Division Winner | 70.5% | 5.5% | -65.05% | $4007k |
Platform profiles at a glance
Funding, scale, regulation, fees, payments — both venues side-by-side. Updated 2025 Q4 from public filings, official sites, and third-party trackers (Crunchbase, Wikipedia).
Feature-by-feature comparison
| Dimension | Kalshi | Polymarket |
|---|---|---|
| Category | prediction market | prediction market |
| Founded | 2018 | 2020 |
| Headquarters | New York, NY | New York, NY (engineering) · Cayman Islands (legal entity) |
| Regulator | Commodity Futures Trading Commission (CFTC) | CFTC — US access via QCEX, the CFTC-licensed exchange + clearinghouse Polymarket acquired in July 2025 |
| States available | All 50 US states | US access relaunched 2025 via Polymarket US (18+, not available in all jurisdictions) + most international markets |
| Monthly volume | ~$200M+ (sports + politics combined, peaks during major events) | ~$200M+ average; spikes to $1B+ on major political event months |
| Annual volume | $1B+ (2024 — driven by ~$430M on the US presidential market alone) | $8B+ in 2024 (driven by the US presidential election cycle) |
| Total raised | $50M+ across Series A–C | $2B+ including Intercontinental Exchange's strategic investment (Oct 2025); $70M+ across earlier rounds |
| Reported valuation | ~$2B (reported, 2025) | ~$9B (reported at the ICE investment, Oct 2025) |
| Parent company | Independent | Independent |
| Public ticker | Private | Private |
| Fee structure | 0.07% per side, capped at 7¢/contract; 2¢ near 50% probability | 0% trading fee + Polygon gas (~$0.01–$0.50 per trade) |
| Min position | $0.01 (1 contract × $0.01–$0.99 YES/NO) | $1 USDC (or whatever the smallest order book allows) |
| Max position | Limited only by orderbook depth — no per-user account caps | Limited only by orderbook depth — no per-user account caps |
| Settlement | USD | USDC (Polygon network) |
| Withdrawal | 1–3 business days via ACH; same-day for wire | Instant on-chain; off-ramp to fiat depends on partner (minutes to a few days) |
| Payments | ACH (Plaid), Debit card, Wire transfer (high-volume) | Polymarket US app funding (US users, post-2025 relaunch), USDC on Polygon (bridge from any chain), Credit/debit card on-ramp via partners |
| Mobile apps | iOS (App Store), Android (Google Play) | iOS (Polymarket US app in the US; international app elsewhere) + responsive web |
| Product categories | Sports, Politics, Climate, Economics (+2 more) | Politics, Sports, Crypto, World Events (+2 more) |
Use Kalshi when…
- US users in states where sportsbooks aren't licensed (CA, TX, HI)
- Sharp users who get limited at FanDuel/DraftKings
- Anyone who wants no-vig pricing on championship/MVP/season-long markets
- Traders who want to short an outcome (sell YES) without needing to find the opposite-side book
Use Polymarket when…
- Traders who want the deepest global political and world-event markets
- Crypto-native users who already hold USDC on Polygon
- US users on iOS (Polymarket US app) after the 2025 relaunch
- Builders / quants who need a clean public API + on-chain data
Strengths and trade-offs
Kalshi strengths
- Only federally regulated US prediction market — works in every state
- No vig / no house edge — peer-to-peer pricing
- USD settlement direct to bank — no crypto required
- No per-user limits — sharps don't get throttled the way sportsbooks throttle winners
- Mobile apps with full feature parity (place, trade, settle from phone)
Kalshi trade-offs
- Thinner sports market coverage than DraftKings/FanDuel on game-level props
- Lower liquidity on niche markets — spreads can be 5¢+ on illiquid contracts
- Newer to sports — settlement disputes occasionally arise on non-canonical sources
- Cannot place same-game parlays/combos — single-contract structure only
Polymarket strengths
- Largest liquidity on US political and international event markets
- Zero trading fees — only pay Polygon gas (~pennies)
- Transparent on-chain order book — every trade publicly verifiable
- Strong API + data feed; institutional-grade tooling
- Backed by top-tier VCs (Founders Fund, Vitalik) and operating since 2020
Polymarket trade-offs
- US re-entry is recent — the Polymarket US product surface is still converging with the international platform
- Self-custodial wallets on the international platform carry smart-contract + key-management risk
- US sports vertical depth is still thinner than Kalshi's on some game-level markets
- International rails settle in USDC — the crypto on-ramp adds friction vs ACH
- Not available in all jurisdictions; promo offers carry their own eligibility restrictions
Frequently asked questions
- What's the core difference between Kalshi and Polymarket?
- Kalshi is a CFTC-regulated US event-contract exchange (Designated Contract Market, same legal classification as the CME) that settles in USD via ACH. Polymarket is a peer-to-peer prediction market that runs on the Polygon blockchain and settles in USDC. Kalshi operates legally in all 50 US states; Polymarket geo-blocks US users after a January 2022 CFTC settlement. The pricing mechanism is structurally similar — both are YES/NO order books with no house counterparty — but liquidity, fees, and user demographics differ enough that the same contract often prices 1–5 percentage points apart.
- Can US residents legally use Polymarket?
- Officially, no. Polymarket settled with the CFTC in January 2022 for $1.4M and agreed to geo-block US IP addresses. Some US users circumvent the block via VPN, but doing so violates Polymarket's terms of service, places funds in a jurisdiction with no US consumer-protection framework, and forfeits any US regulatory dispute path. For legal US event-contract trading, Kalshi is the answer — it's federally regulated by the CFTC and operates in every state.
- How is the Kalshi vs Polymarket edge calculated on this page?
- For each contestant on each active sports event, we pull the latest Kalshi implied probability (de-vigged from bid/ask midpoint when both sides are quoted, or the last trade price otherwise) and the latest Polymarket implied price (YES contract price). Edge = Polymarket probability − Kalshi probability. A positive edge means Kalshi is pricing the outcome cheaper — buy YES on Kalshi to capture the spread. A negative edge means Polymarket is cheaper.
- Why don't all sports events show up in the comparison?
- Polymarket and Kalshi don't cover the same markets one-for-one. We only show rows where BOTH exchanges have a current quote on the same contestant in the same market. Polymarket has historically been heavier on US politics and international markets, while Kalshi has deeper US sports vertical depth. League hub pages (e.g. /sports/nba) show the full Kalshi market — this page is just the overlap.
- Which has cheaper fees: Kalshi or Polymarket?
- Depends on position size. Polymarket charges 0% trading fees but you pay Polygon gas (~$0.01–$0.50 per trade) plus on/off-ramp friction if moving between USD and USDC. Kalshi charges 0.07% per side capped at 7¢ per contract (peaks at ~2¢ near 50% probability) but settles directly in USD with no chain costs. For positions over ~30 contracts, Kalshi tends to be cheaper. For small recurring positions, Polymarket's no-fee model often wins net of gas.
- Do Kalshi and Polymarket prices differ on the same event?
- Yes — often by 1–5 percentage points on liquid markets, sometimes more on illiquid ones. The gap reflects (a) different user bases (Polymarket is more crypto-native and international; Kalshi is US retail), (b) different fee structures that affect marginal traders' break-even, (c) settlement-currency friction (you can't trivially move dollars to USDC and back), and (d) regulatory arbitrage (US sharps blocked from Polymarket can only express views on Kalshi). SportsBookISH surfaces these gaps whenever both venues list the same market.
- Is Polymarket safer than Kalshi?
- From a US regulatory perspective: no. Kalshi is CFTC-registered as a Designated Contract Market with full federal oversight, customer-fund segregation requirements, and US legal recourse for disputes. Polymarket operates outside US jurisdiction — your funds sit in a self-custodial wallet (smart-contract + key-management risk), and there's no US consumer-protection framework if something goes wrong. From a smart-contract / transparency perspective, Polymarket's contracts have been audited and all trades are publicly verifiable on-chain, which some users prefer.
- Can I arbitrage Kalshi vs Polymarket?
- Theoretically yes when the two venues price the same event meaningfully apart. Practically: capital lock-up across two platforms in two currencies (USD on Kalshi, USDC on Polymarket), gas fees on Polymarket, and counterparty risk on both sides eat most of the edge for retail-size positions. The arbitrage is real on big political events with 5%+ spreads — but for sports the most reliable signal is using each venue's price as a check on the other rather than capital-intensive arb execution.
- Which platform has bigger volume?
- Polymarket has historically traded larger volume — about $8B in 2024, driven primarily by the US presidential election cycle (~$3.6B on Trump vs Harris alone). Kalshi's 2024 volume was roughly $1B, but its US sports vertical launched in late 2024 and grew rapidly through 2025. By raw monthly average, Polymarket is bigger; by US-onshore monthly average, Kalshi leads.
- Which has better political markets vs sports markets?
- Politics: Polymarket — both by volume and breadth. Polymarket has historically led on election, primary, and congressional markets with hundreds of millions in volume per major cycle. Sports: Kalshi — deeper US sports coverage with championship futures, MVP, conference winners, and recently per-game markets across all major US leagues. For PGA Tour, Kalshi was first to integrate full-tournament outrights with Top 5/10/20/40 + Make Cut + matchups.
Sources and further reading
All figures best-effort as of 2025-Q4. Funding totals, valuations, and volume are sourced from public filings, official company communications, and third-party trackers (Crunchbase, Wikipedia). Re-verify against primary sources before quoting in compliance-sensitive contexts.