Kalshi vs Polymarket (2026): Which Prediction Market Should You Use?

If you've spent any time around prediction markets in the last couple of years, you already know the two names that keep coming up. Kalshi and Polymarket. They both let you trade on real-world outcomes — elections, sports, economics, whatever — but the way they work, who can access them, and what they charge are completely different stories.

I'm going to lay this out as clearly as I can, because there's a lot of outdated and just plain wrong information floating around online. Especially on the US access question, which changed recently.

Together, Kalshi and Polymarket now control roughly 79% of the total prediction market — an industry that's grown to $127.5 billion in notional volume with nearly 2.5 million unique users. Both companies are currently in fundraising talks that could value each of them at around $20 billion. This is no longer a niche.

What Is Kalshi?

Kalshi was founded back in 2018 by Tarek Mansour and Luana Lopes Lara. They spent a few years navigating regulators, got their CFTC designated contract market license in 2020, and launched publicly in July 2021. That makes them the first — and for a while the only — federally regulated prediction market in the US.

Everything about Kalshi is designed to feel like a financial exchange. You deposit dollars. You trade in dollars. You withdraw in dollars. No crypto wallet needed. KYC is mandatory, which adds a bit of friction up front but also means you have proper regulatory protection if something goes wrong. For people who've been asking "is Kalshi legit?" — yes, it's a CFTC-regulated exchange with the same oversight as traditional futures markets.

In December 2025, Kalshi closed a $1 billion funding round at an $11 billion valuation — up from $5 billion just two months earlier. Weekly trading volumes now sit consistently around $2 billion. A huge chunk of that is sports — Kalshi has leaned into sports markets hard since winning its legal battle against the major US sports leagues in 2024.

Where Kalshi fits: US users who want to trade legally, in USD, with full regulatory backing. If you want a proper Kalshi review — we've got a detailed one coming.

What Is Polymarket?

Polymarket launched in 2020 as a decentralised prediction market running on the Polygon blockchain. You trade with USDC, a dollar-pegged stablecoin. If you've been in crypto for a while this feels natural. If you haven't, there's a learning curve.

The platform went supernova during the 2024 US presidential election, processing roughly $3.7 billion in volume on the election market alone. Nothing else in the prediction market space has come close to that kind of liquidity. When a major event is playing out — an election night, a Fed decision, a playoff game — Polymarket's order books are deep enough that even six-figure positions move prices minimally. Polymarket was most recently valued at $9 billion.

Now, the big change. Polymarket was blocked in the US from 2022 until late 2025, following a CFTC settlement. A lot of Americans were using VPNs to get around it. That era is over. In July 2025, Polymarket completed a $112 million acquisition of QCEX, a CFTC-licensed exchange, which gave them the regulatory path to re-enter the US market. US access started rolling out via a waitlist in late 2025.

But — and this matters — it's not a clean green light everywhere. Some states are pushing back hard. Nevada's Gaming Control Board secured a temporary restraining order against Polymarket in January 2026. Tennessee and Massachusetts have also raised legal challenges. Federal approval doesn't mean every state has agreed to play nice.

For US users on the waitlisted exchange, KYC is now required and trading goes through approved brokers rather than direct crypto wallets.

Where Polymarket fits: Traders who want the deepest liquidity and widest market selection — globally, or in US states where access is confirmed. Full Polymarket review coming soon.

Kalshi vs Polymarket: Key Differences

Kalshi vs Polymarket: Fees Compared

This is where a lot of articles get it wrong, so let me be specific.

Kalshi uses a per-contract fee model. The maximum fee is $0.02 per contract. Fees are calculated based on contract price, with the most common price point (50 cents) costing about $1.75 per 100 contracts. There are separate taker fees (when you match existing orders) and maker fees (when your order sits on the book waiting to be filled). Makers pay less. Deposits via ACH or wire are free; debit card deposits carry a 2% fee.

Polymarket is more interesting on fees because it depends heavily on what you're trading. Most standard markets — politics, world events, long-running contracts — have no trading fees at all. Zero. That's been a huge draw. In early 2026, Polymarket started introducing taker fees on high-frequency markets: up to 3% on 15-minute crypto prediction markets, and some sports markets are also now carrying fees. On the US exchange, the structure is much simpler — 0.10% taker fee, with an equivalent 0.10% maker rebate. No deposit or withdrawal fees on either version.

So who's cheaper? For most casual trading on standard markets, Polymarket still costs less — often nothing. For active trading on Kalshi, the per-contract model is predictable and the maker discount rewards patience. There's no single answer here. It depends entirely on what you trade and how often.

What Markets Can You Trade?

Polymarket has more markets. By a lot. At any given time there are thousands of active contracts covering everything from which country's leader will resign next to whether a specific rapper's album drops this month. If something is in the news, someone's probably already made a Polymarket market on it.

Kalshi takes a different approach. Markets are curated and go through a regulatory review process. You won't find meme-tier speculation, but what you do find tends to be properly structured — clear resolution criteria, formal settlement, less ambiguity. For events like Fed rate decisions, weather events, and major political outcomes, Kalshi's markets are tight and well-designed.

Sports deserves its own note. Kalshi now generates a massive share of its volume from sports markets — it's become the dominant category on the platform since they won their legal battle in 2024. Polymarket has sports markets too, with real volume in leagues like the Premier League and NBA. If you're specifically looking for the best prediction market for sports, both are live options now, but Kalshi has the regulatory edge for US bettors.

People sometimes wonder whether prediction market trading is gambling. Regulators have drawn a distinction: Kalshi's contracts are classified as event contracts under CFTC oversight, not as gambling products. Polymarket occupies a greyer space — it's federally approved now, but some state gambling regulators disagree with that classification, which is exactly why Nevada went after them. "Is Kalshi gambling?" is a legal question with a specific answer: under federal law, no. Under some state interpretations, the line is blurrier.

Liquidity: Where the Money Is

This used to be a one-sided conversation. Polymarket had the liquidity, Kalshi didn't. It's more nuanced now.

Polymarket still wins on major global events. During the 2024 election cycle, the depth of their order books was genuinely unprecedented for a prediction market. For large positions on headline events, Polymarket gives you better fills with less slippage.

Kalshi has closed the gap significantly on US-centric markets though. On things like government shutdown probabilities, Fed meeting outcomes, and US sports events, Kalshi's liquidity is now competitive. The $11 billion valuation and institutional investor base are bringing in bigger traders who want the comfort of a regulated exchange — and bigger traders bring deeper books.

If you're trading five-figure positions on a US election, Polymarket is probably still the play. If you're trading a Fed rate decision and you're based in the US, Kalshi might actually have better depth now.

Can You Use Both Kalshi and Polymarket?

Most of the comparison articles online pretend you have to pick one. You really don't.

The serious traders I know use both. They watch Kalshi for US-regulated markets with clean contracts and Polymarket for the liquidity and market variety. Sometimes the same event is priced differently on both platforms — and that spread is either an arbitrage opportunity or a signal that one market knows something the other doesn't.

The actual pain point is operational. You've got positions on two platforms (maybe three if you're also on Manifold), two sets of login credentials, two different P&L views, and no clean way to see your total exposure. It's a mess unless you're running a spreadsheet, which nobody enjoys doing.

predictions.io was built for exactly this. It aggregates live markets across Kalshi, Polymarket, Manifold, and others — so you can compare prices across platforms in one view. More importantly, it syncs your transactions automatically and gives you a single P&L dashboard across everything you're trading on. You can also follow specific traders and see how they're positioned, which is useful when you're trying to figure out whether a price move is smart money or noise.

Bottom Line

Kalshi is the safer, more straightforward choice for US traders. Regulated, dollar-denominated, no crypto knowledge required. The trade-off is a smaller market selection and slightly less liquidity on global events.

Polymarket is the platform for traders who want breadth, depth, and are comfortable in a crypto environment. US access is back but still messy depending on your state. For everyone outside the US, it's the obvious default.

If you want the most complete picture of what the prediction markets are saying about any given event — or if you're already trading on multiple platforms and want to stop juggling tabs — predictions.io pulls it all together.

Frequently Asked Questions

Is Kalshi or Polymarket better?

Neither is universally better. Kalshi is the right choice for US traders who want full regulation and USD deposits. Polymarket offers deeper liquidity and more markets. Most active traders end up using both platforms, which is why tools like predictions.io exist — to track everything in one place.

Can I use Polymarket in the US in 2026?

Yes, but with caveats. Polymarket received federal CFTC approval in late 2025 after acquiring QCEX. US access is rolling out through a waitlist, requires KYC, and goes through approved brokers. Some states — including Nevada, Tennessee, and Massachusetts — are challenging Polymarket's legality at the state level. Check your state's current status before trading.

What are Kalshi's fees?

Kalshi charges per-contract fees capped at $0.02. The exact amount depends on the contract price and whether you're a maker or taker. Takers pay more; makers get a discount. Deposits via ACH or wire are free. Debit card deposits carry a 2% fee. There are no fees on withdrawals.

Is Polymarket safe?

Polymarket runs on the Polygon blockchain and has been operating since 2020 without a major security incident. It processed $3.7 billion during the 2024 election cycle. The platform is now CFTC-approved for the US market. The main risks are regulatory (state-level legal challenges) and the general risks of interacting with crypto protocols. For the US exchange specifically, KYC and regulated broker access add a layer of protection.

Which prediction market has the most liquidity?

Polymarket. Especially on major global events like elections, it has the deepest order books in the industry. Kalshi is competitive on US-specific markets like Fed rate decisions and sports, but Polymarket's overall volume is higher.

Want to track your positions across both platforms in one dashboard? predictions.io aggregates Kalshi and Polymarket markets in real time — and syncs your P&L automatically.

Last updated: March 2026. Prediction market regulations are evolving quickly — check current availability in your jurisdiction before trading.