If you are in the US and choosing between Polymarket and Kalshi in April 2026, the decision is largely made for you. Kalshi is open, regulated, and serving around 42 states. Polymarket US is in invite-only beta, sports-only, with a reported waitlist of over one million people. Both sit on top of the US prediction-markets industry, both are valued in the billions, both are federally approved — but only one is something you can actually sign up to and trade on today.
That is the headline answer. The longer answer is more interesting because the two platforms have taken fundamentally different routes to the same destination, and the consequences of those routes show up in fees, liquidity, regulation, UX, and which markets you can actually trade. Kalshi has operated inside the US regulatory perimeter since day one and holds roughly 90% of the US prediction-markets market share by volume. Polymarket built its $33 billion-plus in 2025 global volume on crypto rails from an offshore base, then paid $112 million to buy a CFTC-licensed exchange and re-enter the US. The Kalshi you sign up to is the same product US users have been using since 2021. The Polymarket you would sign up to in the US is a new, restricted product — not the same thing as the Polymarket your friends in Europe might have used.
For UK users, the answer is simpler and more disappointing. Neither platform is available to you. Both geoblock the UK for regulatory reasons we covered in our guide to whether prediction markets are legal in the UK. What follows is a comparison written for anyone trying to understand the two platforms — whether you are a US user choosing where to trade, a UK user assessing them from a distance, or simply trying to make sense of two companies that regularly feature in the financial press.
This is an educational guide, not financial or legal advice. Numbers below are accurate as of late April 2026 but prediction-market companies move fast — always check a platform's own current terms before sending real money.
The short answer
For US traders who want access today: Kalshi. You can sign up, fund with a bank account, and trade within the hour. Coverage includes sports, politics, economics, crypto, climate, and mention markets. Commission structure is per-contract and tiered — expect fees of around $0.02–$0.04 per contract on most trades, capped at $1.75 per 100 contracts for takers.
For US traders who want Polymarket specifically and are willing to wait: join the waitlist. Polymarket US currently offers sports markets only and remains invite-gated as of April 2026. The platform's headline attraction is a flat 0.10% taker-only fee on contract value — materially cheaper than Kalshi for trades priced near 50¢. When Polymarket US fully rolls out, the calculus will shift. Until then, it is a promise rather than a product for most people.
For UK traders: both are view-only. Polymarket lets you browse markets, Kalshi blocks the UK at sign-up. Betfair Exchange is the closest UK-legal equivalent for political markets.
Access and availability
Kalshi
Kalshi operates as a CFTC-regulated designated contract market and is available in 42 states as of April 2026. The platform handles identity verification and funding through traditional banking rails — ACH, debit card, wire transfer, Apple Pay, and crypto deposits that convert to USD on arrival. Account opening takes minutes rather than days, which is a quiet but meaningful advantage. You do not need a crypto wallet, you do not need to understand gas fees, and your balance is denominated in dollars.
The exclusions matter. State-level pushback against Kalshi has been significant in 2025 and 2026. Nevada obtained a temporary injunction in March 2026 prohibiting Kalshi from taking bets from Nevada residents. Massachusetts, Tennessee, Ohio, and Arizona have all mounted enforcement actions. The results have been mixed — Kalshi won preliminary injunctions in Tennessee and New Jersey, lost in Ohio and Nevada, and the Massachusetts case is heading for appeal. The federal preemption question underlying these cases is widely expected to reach the Supreme Court in 2026 or 2027.
For most US users in most states, none of this affects day-to-day access. The platform works. The litigation matters primarily for traders in states where Kalshi is currently excluded or at risk of exclusion. For the full state-by-state breakdown, see our guide to whether prediction markets are legal in the US.
Polymarket US
Polymarket's US product is a different animal from its offshore platform. In July 2025 the company acquired QCEX — a CFTC-licensed derivatives exchange — for $112 million. The CFTC issued an Amended Order of Designation in November 2025 and Polymarket announced a beta launch in January 2026. As of April 2026 that beta remains invite-only, sports-only, and mobile-only. The company has provided no public timeline for full rollout or expanded category coverage.
Hundreds of thousands of users are on the waitlist. Invite codes circulate publicly — the most common route in currently is via affiliate codes from sportsbook-review sites. The product itself, once you have access, is functional but limited. Sports markets on the major US leagues, a flat 0.10% taker fee, wallet-based funding via USDC or similar stablecoins. If you want elections, economics, crypto contracts, or global events, you are waiting for a future rollout that has no announced date.
Polymarket offshore (the original)
The main Polymarket brand — the one that processed $33.4 billion in 2025 volume and became a fixture of the 2024 US election news cycle — is a separate product. It operates on the Polygon blockchain using USDC, runs 350,000-plus active markets across every category, and is available internationally with the usual set of restricted jurisdictions (US, UK, Germany, France, Italy, Netherlands, Belgium, and about 40 others). For most readers of this article, offshore Polymarket is interesting context but not a platform you can use — if you are in a restricted country, attempting to access it violates the Terms of Use and will get your account terminated.
Fees and costs
The two platforms have fundamentally different fee structures and neither is universally cheaper — it depends on what you trade.
Kalshi's fee formula is: 0.07 × contracts × price × (1 − price), capped at $1.75 per 100 contracts for takers and $0.44 for makers. Because price appears as p × (1−p) in the formula, fees peak on contracts priced near 50¢ and drop sharply on contracts priced near the extremes. A 90¢/10¢ contract costs almost nothing to trade. A 50¢/50¢ contract is at the fee peak.
Polymarket US charges a flat 0.10% taker-only fee on total contract value. For a 50¢ contract, that is 0.05¢ per contract — cheaper than Kalshi. For an 80¢ contract, that is 0.08¢ — close to Kalshi but still slightly cheaper. The flat model means Polymarket US is consistently the lower-cost option for any single trade at typical retail size, though the per-trade difference is in pennies. For very active traders the cumulative savings matter. For casual users placing a few trades a month, the difference is immaterial.
A more important point: Kalshi has no deposit or withdrawal fees. Polymarket US uses crypto rails, which means gas fees on the underlying blockchain for wallet operations. These are typically small but non-zero and they add up. Kalshi is the simpler cost structure to reason about.
Liquidity and market depth
Kalshi has deeper liquidity in sports and macro markets, which together account for around 90% of its volume. The order books in its headline NFL, NBA, and economics markets regularly absorb institutional-sized orders without meaningful slippage. Spreads are tight. For traders placing $1,000 to $50,000 at a time in major markets, Kalshi is the more reliable execution venue today — simply because it has had three more years of operation and a larger active user base.
Polymarket offshore remains the deepest market globally for politics and long-tail events — the 2024 election drove weekly volumes above $2 billion for multiple consecutive weeks, and the category mix is genuinely distributed (around 60% of volume comes from outside sports). But that liquidity does not transfer to Polymarket US, which is a separate product with a separate user base. Polymarket US is in beta. Its liquidity is shallow and concentrated in a handful of sports markets.
The takeaway: if you want deep liquidity in the US today, Kalshi. If you want deep liquidity in politics or global events, Polymarket offshore — which you cannot legally access from the US, UK, or most European markets.
Markets and categories
Kalshi's market coverage is broader than Polymarket US's by a wide margin. Sports, politics, economics, crypto, climate, entertainment, and mention markets are all live. The mention markets are particularly distinctive — contracts on whether specific words or phrases will appear in speeches, press conferences, or Federal Reserve statements. Kalshi launched these in late 2025 and they have grown to volumes comparable to smaller sporting events.
Polymarket US is currently sports-only. This is a regulatory and operational choice — the full product is designed to offer the same breadth as the offshore version, but roll-out is staged. Expect categories to expand through 2026 but treat specific timelines with scepticism until the company announces them.
For anyone whose interest is political markets specifically, the honest answer for US users is that Kalshi is your option until Polymarket US expands. For UK users, Betfair Exchange has run political markets since 2000 and remains the deepest UK-legal venue for UK and US political contracts — though the UX is noticeably more dated than either Kalshi or Polymarket. For background on how prediction markets work as a category, see our guide to what prediction markets are.
Regulation and trust
Both platforms are now federally regulated in the US under the CFTC. The difference is how long they have been there and how contested that regulation is.
Kalshi has been CFTC-designated since 2020 and has the longer track record. Its institutional backing — Sequoia, Paradigm, Charles Schwab among the Series E investors at an $11 billion valuation — reflects that maturity. The live regulatory risk for Kalshi is state-level: the series of state gambling-law challenges that will ultimately reach the Supreme Court. A ruling against federal preemption would force Kalshi to license state-by-state with individual gaming commissions, which would materially change its cost structure and state coverage.
Polymarket US is newer to CFTC regulation — approved November 2025, operational January 2026. The platform inherits the QCEX CFTC licence it acquired rather than building from scratch. Its offshore parent continues to operate with a separate legal and regulatory identity. Polymarket's main strategic risk is different from Kalshi's: the planned crypto token launch. The token introduces both a growth lever (airdrops incentivise user activity) and a complication (regulators scrutinise whether activity is organic or incentivised). How the SEC and CFTC treat the token when it launches will matter for the company's long-term trajectory.
What this means in practice
If you are a US user who wants to trade prediction markets today, Kalshi is the obvious answer. It works, it is regulated, it has the markets and the liquidity, and your account will be up and funded the same day. Polymarket US is for users who specifically want early access to the product, are willing to wait for invites, and can operate comfortably with crypto wallets. Both are credible businesses. One is available to you, the other is aspirational.
If you are a UK user, neither is currently available for trading. Betfair Exchange is the practical alternative for political markets. Smarkets is the commission-friendly alternative for smaller positions. Matchbook's announced 2026 UK prediction-markets platform is the one to watch.
If you are simply trying to understand the space: Kalshi is the boring, compliant, traditional-finance-looking product. Polymarket is the crypto-native, permissionless-feeling product that has taken a more circuitous route to US compliance. Both will probably matter for years. Whether one takes the whole market or they split it is the commercial question investors are pricing right now, and the recent divergence in their valuations — Kalshi $11B, Polymarket reportedly valued around $7B less — suggests the market is tilting toward Kalshi on near-term execution but leaving room for Polymarket to close the gap if the US rollout delivers.
Frequently asked questions
Is Kalshi better than Polymarket?
For US users in April 2026, Kalshi is the more practical choice — it is open, regulated, available in around 42 states, and you can sign up and trade the same day. Polymarket US is invite-only, sports-only, and gated behind a waitlist of over a million people. The picture changes if you can get into Polymarket US: the flat 0.10% taker fee is materially lower than Kalshi's per-contract fees on most trades. "Better" depends on whether you value access today or fee structure tomorrow.
Can I use both Kalshi and Polymarket?
Yes. The two platforms have separate accounts, separate funding, and different market coverage, so it is common for active traders to maintain accounts on both and route orders to whichever has the better price or deeper book on a given contract. Note that Polymarket US currently requires an invite, and the offshore Polymarket platform that operates internationally is not legally accessible to US, UK, or most European residents — using a VPN to access it violates the Terms of Use and will get your account terminated.
Is Polymarket available in the US?
Yes, but in a limited beta. Polymarket acquired QCEX, a CFTC-licensed exchange, for $112 million in July 2025, received its Amended Order of Designation from the CFTC in November 2025, and launched a US beta in January 2026. As of April 2026 the product is invite-only, sports-only, and mobile-only, with a waitlist of hundreds of thousands of users. Full rollout has no announced date. Polymarket US is a separate product from the offshore Polymarket platform that powered the 2024 election cycle.
Can UK users access Polymarket or Kalshi?
No. Both platforms geoblock UK users at the trading level. Polymarket lets you browse markets in view-only mode but blocks signup and deposit; Kalshi blocks signup outright with a notice listing the United Kingdom on its prohibited-countries page. The regulatory reason is the FCA's 2019 ban on binary options to retail consumers. UK users wanting similar products can use Betfair Exchange or Smarkets, both UKGC-licensed betting exchanges with mechanically similar order books.
What are the fees on Polymarket vs Kalshi?
Kalshi's fee formula is 0.07 × contracts × price × (1 − price), capped at $1.75 per 100 contracts for takers and $0.44 for makers. Fees peak on contracts priced near 50¢ and drop sharply near the extremes. Polymarket US charges a flat 0.10% taker-only fee on contract value, which works out cheaper than Kalshi for most trades priced between 30¢ and 70¢. Both platforms have no deposit or withdrawal fees, though Polymarket uses crypto rails so blockchain gas fees apply on wallet operations.
How iPredicta fits in
iPredicta is a prediction-markets discovery and intelligence platform. We aggregate Polymarket, Kalshi, and other venues so you can see the best available price across platforms on any given contract, flag arbitrage opportunities when they appear, and understand which platforms you can actually use from your jurisdiction. When Polymarket US rolls out more widely or Kalshi's state coverage changes, we will reflect that live. Our job is to help you act on the information — not to sell you one platform over another.