Kalshi and Polymarket are the two largest prediction markets in the world, and the core difference is how they are built: Kalshi is a US dollar exchange regulated directly by the Commodity Futures Trading Commission (CFTC), while Polymarket is a crypto-native platform that settles trades in stablecoins and only returned to US users at the end of 2025. In practice, Kalshi dominates sports and economic contracts for American traders, while Polymarket runs the deepest global markets for politics and world events.

This comparison explains how each platform works, who can legally use them, how their fees and funding differ, and which one leads on trading volume as of July 2026.

Key takeaways

  • Both trade the same instrument — event contracts — yes/no positions that settle at $1 if you’re right and $0 if you’re wrong, with the price acting as the market’s implied probability.
  • Regulation is the dividing line. Kalshi is a CFTC-regulated Designated Contract Market; Polymarket ran offshore until it acquired a CFTC-licensed exchange (QCEX) for $112 million in July 2025 and launched Polymarket US in December 2025.
  • Funding differs. Kalshi takes US dollars by bank transfer, card, or PayPal; Polymarket International settles in USDC stablecoin on the Polygon blockchain.
  • They specialize differently. Sports made up about 80% of Kalshi’s volume since July 2024 versus 39% for Polymarket, while Polymarket leads decisively in politics and geopolitics.
  • Kalshi leads on volume. In June 2026 Kalshi processed roughly $31.5 billion versus Polymarket’s combined $13.3 billion, though the two count volume differently.

Kalshi vs Polymarket at a glance

The fastest way to see the difference is side by side, as of July 2026:

  • Regulation: Kalshi — CFTC-licensed exchange since 2020. Polymarket — offshore until 2025; now runs a CFTC-regulated US arm alongside its global platform.
  • Funding: Kalshi — US dollars (bank, wire, debit card, PayPal, Venmo). Polymarket International — USDC stablecoin via a crypto wallet on Polygon.
  • US access: Kalshi — nationwide, though sports contracts face state-level challenges. Polymarket — US users returned in December 2025 via Polymarket US.
  • Strengths: Kalshi — sports, inflation, rates, weather, stock indices. Polymarket — politics, geopolitics, crypto prices.
  • Valuation: Kalshi — $22 billion (May 2026 Series F). Polymarket — roughly $8–9 billion after a $2 billion investment from Intercontinental Exchange (ICE), the owner of the New York Stock Exchange.

Everything below unpacks these rows.

How each platform is regulated

The regulatory contrast is the single most important difference between the two. Kalshi was founded in 2018 by Tarek Mansour and Luana Lopes Lara, received its CFTC license in 2020, and has operated the entire time as a federally regulated Designated Contract Market — the same category as a US futures exchange. That status let it serve American users directly and, after a September 2024 court win against the CFTC, list the first legal US election contracts in over a century. We cover that fight and the “markets find truth” thesis in Kalshi and the new Wall Street.

Polymarket, founded in 2020 by Shayne Coplan, took the opposite path. It grew into the world’s largest political prediction market while operating offshore and blocking US users after a 2022 CFTC settlement. To come back onshore, Polymarket acquired the CFTC-licensed exchange and clearinghouse QCEX for $112 million in July 2025, received a CFTC Amended Order of Designation in November 2025, and relaunched for US traders as “Polymarket US” on December 2, 2025. Its main international platform still runs on crypto rails.

How funding and settlement differ

Kalshi behaves like a brokerage: you deposit US dollars through a bank transfer, wire, debit card, or payment apps like PayPal and Venmo, and your balance is denominated in dollars. There is no wallet and no token to manage.

Polymarket’s international platform is crypto-native. Trades settle in USDC, a dollar-pegged stablecoin, on the Polygon blockchain, and users interact through a crypto wallet rather than a traditional brokerage account. This is what historically kept it out of reach for compliant US access and what makes it “permissionless” — anyone can create a market. If you’re new to how dollar-pegged tokens work, our explainer on stablecoins replacing banks covers the mechanics that underpin Polymarket’s settlement layer.

What you can trade: sports vs politics

The two platforms have grown into different specialties. According to Pew Research Center data covering July 2024 to April 2026, sports accounted for roughly 80% of Kalshi’s trading volume, versus about 39% on Polymarket. Politics tells the opposite story: it made up around 32% of Polymarket’s volume against just 4% on Kalshi over the same period, and Polymarket remains the deepest liquidity pool for political and geopolitical event contracts anywhere.

Both list crypto price markets, economic data, and world events, but the practical takeaway is simple. If you want to trade a football game or next month’s inflation print in dollars, Kalshi is the natural home. If you want the sharpest odds on an election, a war, or a policy decision, Polymarket’s global book runs deeper. Kalshi’s aggressive move into sports has also turned it into a direct rival to betting apps — a collision we detail in are prediction markets replacing sportsbooks?.

Fees compared

Neither platform profits by taking the other side of your bet; both earn from trading activity, which keeps their incentives aligned with volume rather than with your losses.

Kalshi charges a taker fee that scales with contract price and peaks near 1.75 cents on a 50-cent contract — roughly a 3.5% round-trip cost at the midpoint — and funding by debit card adds about 2%. Polymarket charges taker fees of roughly $0.75 to $1.75 per 100 shares depending on the category, waives fees on some geopolitics and world-events markets, and pays makers a daily liquidity rebate. For most casual traders the costs are broadly comparable, and the bigger financial variable is usually the funding method, not the per-trade fee.

Which is bigger? Trading volume in 2026

Kalshi leads on headline volume. In June 2026 it processed roughly $31.5 billion in notional volume — up about 87% from May — while Polymarket recorded around $13.3 billion combined ($10.26 billion international plus $3.04 billion on Polymarket US), lifted by a World Cup Winner market that alone reached $3.9 billion by early July 2026. Combined, the two platforms traded about $44.8 billion that month.

One caveat matters when comparing these figures: the platforms measure volume differently. Kalshi reports notional volume, counting every contract at its full $1 face value regardless of the price paid, while Polymarket reports taker notional, multiplying contracts by the price actually paid. Kalshi’s method inherently produces larger numbers, so the raw gap overstates the difference in real dollars changing hands. Even adjusting for that, Kalshi has held a clear lead through most of 2026, and the whole category has exploded — combined volume rose from under $5 billion in September 2025 to more than $44 billion by mid-2026.

Both can now serve US users, but through different legal doors, and the ground is still shifting. Kalshi operates nationwide under its CFTC license; Polymarket serves Americans through its separately regulated Polymarket US arm launched in December 2025. The live dispute is over sports: by early July 2026, at least 11 states had issued warnings or cease-and-desist letters challenging whether sports event contracts amount to unlicensed gambling, and legal fights were underway in more than a dozen states. We map that state-by-state picture in are prediction markets legal in the US?, and cover Kalshi’s mechanics in depth in our guide to what Kalshi is.

Which one should you use?

The choice comes down to what you want to trade and how you want to fund it, as of July 2026:

  • Choose Kalshi if you want to trade in US dollars from a regulated brokerage-style account, and you’re focused on sports, US economic data, or index levels.
  • Choose Polymarket if you want the deepest markets on politics, geopolitics, and world events, and you’re comfortable with a crypto wallet and USDC — or you prefer its dollar-based US version for onshore access.

For many active traders the answer is “both,” using each platform where its liquidity is deepest. Whichever you pick, treat event contracts as a way to price a probability view, not as free money: a losing contract settles at zero, and well-calibrated markets are hard to beat consistently.

Frequently asked questions

What is the main difference between Kalshi and Polymarket?

Kalshi is a US dollar exchange regulated directly by the CFTC, so Americans can fund an account with dollars and trade under federal oversight. Polymarket is a crypto-native platform that settles trades in USDC stablecoin on the Polygon blockchain and only returned to US users in December 2025 through a separately regulated arm, Polymarket US. Kalshi leads in sports and economic contracts, while Polymarket leads in politics and geopolitics.

Is Kalshi bigger than Polymarket in 2026?

Yes, on reported volume. In June 2026 Kalshi processed about $31.5 billion versus Polymarket’s roughly $13.3 billion combined. The gap is partly a measurement effect — Kalshi counts contracts at their full $1 face value while Polymarket counts the price actually paid — but Kalshi has held a clear lead through most of 2026.

Can US users trade on both Kalshi and Polymarket?

Yes, as of July 2026. Kalshi has served US users nationwide since it launched, and Polymarket reopened to Americans in December 2025 via its CFTC-regulated Polymarket US platform. The main uncertainty is around sports contracts, which faced warnings or legal challenges in more than a dozen states by mid-2026.

Which is better for beginners, Kalshi or Polymarket?

For most US beginners, Kalshi is the simpler starting point because it uses regular dollars and a familiar brokerage-style account with no crypto wallet required. Polymarket suits users who already hold stablecoins or want the deepest political markets, and its US version offers a dollar-based alternative for onshore access.

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