Kalshi vs Polymarket

Kalshi and Polymarket are the two biggest prediction markets in the world, and on the surface they look almost identical: you buy shares in an outcome for between 1¢ and 99¢, and each share pays $1 if you’re right. The differences are underneath. They’re regulated differently, they take different money, their fees work slightly differently, and above all they’re open to different people.

The short answer

Kalshi is a US exchange regulated by the Commodity Futures Trading Commission (CFTC). You fund it like a brokerage account, with a bank transfer or card in US dollars (crypto deposits are supported too), and it has expanded to well over 100 countries. It’s the natural choice for most Americans.

Polymarket runs its main exchange on the Polygon blockchain and settles in pUSD, a dollar token backed one-to-one by the USDC stablecoin. It usually has the most volume on politics and world events and the widest range of markets. That main exchange is not open to US residents or to people in a long list of other countries; Americans use a separate, CFTC-regulated Polymarket US app instead.

Side by side

Regulation and safety

Kalshi holds a CFTC licence as a designated contract market, the same category as the big futures exchanges. Customer funds fall under federal segregation rules, you go through standard identity checks, and US rules on market manipulation and record-keeping apply.

Polymarket’s main exchange is different. Trades settle on a public blockchain, and you hold USDC in a wallet attached to your account. In late 2025 Polymarket returned to the US with a CFTC-approved exchange and launched a separate US app, opening it to users from a waitlist and starting with sports. If you’re American, that app is the only way to use Polymarket legally; using a VPN to reach the main exchange breaks its terms and can get your funds frozen.

Neither model is “risk-free”. With Kalshi the risk sits with a US company and its clearing arrangements. With Polymarket’s main exchange you take on stablecoin and smart-contract risk in exchange for fewer middlemen.

Fees: closer than they used to be

For years Polymarket was famous for charging no trading fees. That changed in 2026: it now charges a taker fee on almost every category, while traders who post orders and wait (makers) still pay nothing. Kalshi has charged a similar fee from the start. Both use the same shape of formula:

fee = shares × rate × price × (1 − price)

That means the fee is highest on a coin-flip at 50¢ and shrinks towards zero on near-certain outcomes. Here’s what 100 shares bought at 50¢ costs in fees:

Kalshi rounds its fee up to the next cent and sets some product lines at their own rates, so check the fee preview before you confirm a trade. On either platform you can avoid most fees by placing limit orders and waiting for them to fill instead of taking the best available price.

Getting money in and out

Kalshi

Kalshi works like an online broker. Bank transfers (ACH) are free and take a few business days. Debit cards are instant but carry a processing fee of around 2%. Wires suit larger amounts. Kalshi also accepts USDC deposits on several networks, which are converted to dollars in your account. Withdrawals go back to your bank.

Polymarket

On the main exchange your balance is pUSD, Polymarket’s dollar token backed by USDC; deposits are converted for you. You can send USDC from a crypto exchange or wallet, or buy it inside Polymarket with a card through a payment partner. Polymarket doesn’t charge to deposit or withdraw, but the exchange you send from, the card provider or the network may. If you’ve never used a stablecoin, our guides on USDC and crypto wallets walk through it step by step.

Markets and liquidity

Liquidity, how much money is waiting to trade, matters more than fees for most people: a thin market can cost you several cents in spread before any fee is charged. As a rule of thumb:

• Polymarket tends to have the deepest books on global politics, elections outside the US, crypto prices and pop-culture questions.
• Kalshi is usually strongest on economic data (Fed decisions, inflation, jobs), US sports and short-term questions like weather and daily index levels.
• On the biggest US political races both are deep, and prices usually sit within a few points of each other.

Our live board lists both venues side by side, ranked by volume, so you can see where the action is on any topic right now.

Why the same question can have two prices

When Kalshi and Polymarket list the same event, their prices rarely match exactly. Different users, different money (dollars vs USDC), different fees and slightly different resolution rules all play a part. Gaps of one to three points are normal. Bigger gaps can be an opportunity, but read both markets’ rules first: “by December 31” on one and “in 2026” on the other can resolve differently (see how each platform resolves markets). See every live gap in our price-gap scanner, and the week’s largest in our weekly gap data, which tracks events we have checked are the same question on both venues.

Verdict

FAQ

Fee rates from Polymarket’s documentation and Kalshi’s published fee formula, checked October 2026. Availability details reflect public announcements and court reporting up to that date.