Polymarket vs Kalshi, side by side
Polymarket and Kalshi are the two largest prediction market platforms in 2026, both trading binary YES/NO event contracts from opposite ends of the regulatory spectrum. Polymarket is crypto-native on Polygon with pUSD collateral backed by USDC. Kalshi is a CFTC-regulated Designated Contract Market clearing through Kalshi Klear. Polymarket US (QCX LLC) is now CFTC-listed too — the venues converge on surface area but their liquidity, fees, and settlement rails stay distinct. The table below shows where prices currently disagree.
| Event | Outcome | Polymarket | Kalshi | Diff |
|---|
| Solana price target by end of 2026 | ↑ 160 | 19¢ | 24¢ | −6¢ |
| Bitcoin price target by end of 2026 | ↑ 100,000 | 17¢ | 22¢ | −5¢ |
| 2028 Democratic Presidential Nominee | Rahm Emanuel | 2¢ | 5¢ | −4¢ |
| Bitcoin price target by end of 2026 | ↑ 130,000 | 5¢ | 8¢ | −3¢ |
| Solana price target by end of 2026 | ↑ 180 | 12¢ | 14¢ | −3¢ |
| 2027 NFL Super Bowl Winner | Kansas City Chiefs | 4¢ | 7¢ | −2¢ |
| 2028 US Presidential Election Winner | Gavin Newsom | 16¢ | 14¢ | +2¢ |
| 2028 Democratic Presidential Nominee | J.B. Pritzker | 2¢ | 4¢ | −2¢ |
| Bitcoin price target by end of 2026 | ↑ 110,000 | 13¢ | 15¢ | −2¢ |
| Ethereum price target by end of 2026 | ↑ 4,500 | 10¢ | 8¢ | +2¢ |
| 2028 US Presidential Election Winner | Jon Ossoff | 5¢ | 7¢ | −2¢ |
| 2026 MLB World Series | Milwaukee Brewers | 6¢ | 7¢ | −2¢ |
| 2028 Democratic Presidential Nominee | Mark Kelly | 2¢ | 3¢ | −2¢ |
| Bitcoin price target by end of 2026 | ↑ 150,000 | 4¢ | 6¢ | −2¢ |
| 2028 US Presidential Election Winner | Marco Rubio | 16¢ | 18¢ | −2¢ |
| Bitcoin price target by end of 2026 | ↑ 200,000 | 2¢ | 4¢ | −1¢ |
Two very different answers to the same question
Polymarket and Kalshi both let you trade binary YES/NO contracts on real-world events, but they come from opposite ends of the regulatory and technical spectrum. Understanding that split is the key to knowing which venue suits which trade.
Polymarket — crypto-native, global, onchain
Built on Polygon with tokenized YES/NO positions, a peer-to-peer CLOB, and pUSD collateral backed by USDC. Strongest in politics, crypto, macro, sports, geopolitics, culture, and long-tail news.
Kalshi — CFTC-regulated, US-first, USD settled
A CFTC Designated Contract Market for event contracts: identity-verified accounts, USD settlement through Kalshi Klear. Election contracts cleared 2024–25; sports contracts launched 2025 but remain contested by some state regulators.
Same questions, different prices
Different user bases, funding rails, fees, and contract wording mean similar markets trade at different implied probabilities. A 'Fed cut by December?' market can diverge for hours — but only matching wording and resolution sources make the spread tradeable.
Converging, not identical
Polymarket US (QCX LLC) is now CFTC-listed alongside Kalshi, and Kalshi has expanded into sports and crypto-related markets. The venues converge on surface area, but liquidity pools, fee models, and settlement rails stay distinct — which keeps price divergences alive.
When to pick Polymarket vs Kalshi
Neither platform is strictly better — it depends on where you live, how you custody money, and what you are trying to trade. Here is how experienced users actually split their activity.
Polymarket vs Kalshi at a glance
The differences that actually decide where to route an order — regulation, fees, listing speed, liquidity, and API surface, all in one scannable table.
| Factor | Polymarket | Kalshi |
|---|---|---|
| Federal legality | US DCM listed July 2025 QCX LLC d/b/a Polymarket US is listed by the CFTC as a Designated Contract Market; QC Clearing LLC d/b/a Polymarket Clearing is a registered DCO. | CFTC-approved since 2020 KalshiEX LLC received its CFTC Designated Contract Market order in November 2020 and operates as a regulated US event-contract exchange. |
| State availability | International geoblocks US Polymarket International still lists the United States as blocked for order placement; US access runs through the separate Polymarket US flow for eligible users. | Broad US access, contested categories Available to many US users, but some state regulators are actively contesting or restricting specific categories, especially sports, entertainment, and election-related contracts. |
| Registration & KYC | Full KYC on US platform International trading uses wallet/API credentials and geoblocking; Polymarket US requires identity verification before trading or API-key access. | Full identity verification Identity verification is required for account access, funding, and trading under Kalshi's regulated exchange model. |
| Settlement asset | pUSD on Polygon Polymarket International uses pUSD collateral on Polygon, backed by USDC; winning shares redeem for $1 of collateral. | USD at a regulated clearinghouse Contracts are dollar-denominated and clear through Kalshi Klear; ACH is free, while wires, debit cards, and crypto transfers can involve bank or processor fees. |
| Fees | Category-based taker fees International fees apply only on some markets: fee = C × feeRate × P × (1−P), with geopolitics/world events still fee-free. Polymarket US uses a similar theta formula with maker rebates. | 0.07 × C × P × (1−P) General trading fees use round-up(0.07 × contracts × price × (1−price)); some markets have lower or special schedules and some resting orders have maker fees. |
| Market creation speed | Fast global listings International listings can respond quickly to breaking news because they do not use Kalshi's CFTC self-certification path. | Formal CFTC rule path Kalshi lists through exchange rules and CFTC filings or self-certifications, so new categories and contract designs involve a formal regulatory process. |
| Liquidity profile | Global long-tail depth Often strongest in global politics, crypto, geopolitics, culture, and niche news markets. | US regulated depth Often strongest where US-regulated access, sports volume, economic releases, or brokerage integrations concentrate flow. |
| API & data access | CLOB + Gamma + onchain data International APIs expose Gamma discovery, the CLOB, and onchain outcome-token events; Polymarket US provides separate REST/WebSocket APIs and SDKs. | REST + WebSocket + SDKs REST and WebSocket APIs with API-key/RSA signing plus official Python and TypeScript SDKs — no wallet signing required. |
Sources: CFTC, Kalshi, Polymarket · reviewed May 2026
Fee deep-dive: formulas, categories, and rounding
For active traders, the fee schedule often decides whether a cross-venue spread is real. Current fees are formula-based, vary by market category, and can change around special products — so the exact contract matters.
| Scenario | Polymarket | Kalshi | Practical takeaway |
|---|---|---|---|
| Base trading fee | C × rate × P × (1−P); geopolitics free. US: theta-based. | round up(0.07 × C × P × (1−P)); special schedules apply. | Check per-market fees before sizing trades. |
| Maker order | Intl: free or rebated. US: maker rebates. | Usually free; maker-fee markets charge 0.0175 × C × P × (1−P). | Posting liquidity changes net edge; rules vary by venue. |
| Network / settlement cost | No platform fee; Polygon/bridge costs vary by funding path. | No gas; ACH free; debit/wire/PayPal/crypto routes charge fees. | Funding rails can cost as much as the fee. |
| 100 contracts × $0.20 | $0 geopolitics; $0.48 sports, $0.64 finance, $0.80 general, $1.12 crypto. | $1.12 general; special or maker rules adjust. | The 'Polymarket is free' shortcut no longer holds. |
| 50 trades / $25k month | Varies by category, prices, and maker/taker ratio. | Varies by prices, maker/taker ratio, rounding, and schedules. | Backtest with actual fills; headline rates aren't enough. |
| Tight arbitrage | Check fee flags, category rate, collateral, gas. | Check fee schedule, rounding, maker fees, settlement, state eligibility. | Price gaps die to fees, slippage, or mismatched wording. |
Sources: Polymarket + Kalshi fee docs
Polymarket vs Kalshi Reddit discussions
Selected Reddit threads where traders discuss arbitrage, fees, alerts, liquidity, and execution across Polymarket and Kalshi. Short verbatim quotes; full discussions on Reddit.
consistent arbitrage opportunities sitting there in plain sight.
Found 5¢ arbitrage spreads in prediction markets expiring tomorrow
finding the spread is easy, executing it before it closes is the hard part.
Automating the Prediction Market Arb: Programmatically capturing the 5% spread
Feels like there should be a single place to see all the prices at once.
Anyone else cross-referencing Poly and Kalshi on the same market to find better odds?
If the same event is priced differently on Kalshi vs Polymarket that's free edge.
How I research Kalshi and Polymarket markets before placing a trade
consistent arbitrage opportunities sitting there in plain sight.
Found 5¢ arbitrage spreads in prediction markets expiring tomorrow
finding the spread is easy, executing it before it closes is the hard part.
Automating the Prediction Market Arb: Programmatically capturing the 5% spread
Feels like there should be a single place to see all the prices at once.
Anyone else cross-referencing Poly and Kalshi on the same market to find better odds?
If the same event is priced differently on Kalshi vs Polymarket that's free edge.
How I research Kalshi and Polymarket markets before placing a trade
How Parlay screens a real spread
A price gap only becomes actionable after fees, liquidity, settlement timing, and wording are checked. This demo card uses a recent Polymarket/Kalshi snapshot to show how Parlay frames a cross-venue spread with a fee buffer before you review the live market.
Polymarket vs Kalshi FAQ
The questions new traders ask first — including the ones that dominate the arbitrage threads on r/PredictionMarkets.
Stop tab-switching between Polymarket and Kalshi
Parlay watches both exchanges at once, normalizes their markets, and highlights where prices disagree. Spot cross-venue candidates, check liquidity and fee buffers, and let your agents reason over the whole prediction-market landscape — not just one venue.