Kalshi vs Polymarket: Which is the best platform for prediction markets in the US?

Kalshi and Polymarket are two of the most dominant prediction markets platforms in the US today. However, while both platforms allow users to trade real-world outcomes, ranging from Federal Reserve rate decisions to Bitcoin price targets, their operating models are very different. 

Here, we are going to explore the differences between Kalshi and Polymarket. Is one platform better than the other for traders based in the US? 

Headquarters and operations 

Kalshi was founded in 2018 (and launched in 2019) by MIT graduates Tarek Mansour and Luana Lopes Lara. Based and headquartered in New York, it operates as a Designated Contract Market (DCM), running on traditional US banking infrastructure and settling trades in US dollars.  

Polymarket was founded a few years later in 2020 by American entrepreneur Shayne Coplan. It is also based in NYC; however, it is legally domiciled in Panama through an offshore operating entity and it functions as a crypto-native platform, executing and settling trades via smart contracts on the Polygon blockchain using the USDC stablecoin. 

Regulation 

Because Kalshi was founded as a US-first exchange, it is registered with the Commodity Futures Trading Commission (CFTC) as a Designated Contract Market (DCM). Today, it operates legally in the US with full regulatory oversight. 

By contrast, Polymarket’s main international platform is geo-blocked for US IP addresses today to comply with CFTC settlement commitments. US traders can access its CFTC-regulated exchange, QCX, however. 

Account funding

For account funding, Kalshi relies primarily on traditional US fiat rails, allowing users to deposit US dollars directly via ACH bank transfers, debit cards, wire transfers, Apple Pay/Google Pay, PayPal, Venmo, and Cash App (as well as crypto through its custodian partner Zero Hash). 

Polymarket, on the other hand, operates on a crypto-native infrastructure where users fund their accounts by transferring USDC directly from an external digital assets wallet or purchasing crypto on-platform using a credit card, debit card, or bank transfer via integrated fiat-to-crypto payment gateways. 

Pricing and spreads

Both Polymarket and Kalshi price contracts binary-style between $0.01 and $0.99 where the price reflects the probability of a certain event occurring. So, for example, if a contract is priced at $0.65, it tells us that there is a 65% chance of the event happening. 

If the event occurs, the contract will settle for $1.00. However, if it doesn’t occur, the contract will settle at $0.00.

In terms of spreads, on high-profile macroeconomic and financial events such as S&P 500 daily ranges, Bitcoin price thresholds, and Federal Reserve decisions, Polymarket generally exhibits tighter bid-ask spreads. This is because it attracts a larger, global pool of traders who can buy and sell 24/7 using cryptocurrency.

Kalshi’s spreads on S&P 500 and FX markets are generally competitive during regular US trading hours. However, they can be wider during off-hours, on weekends, or during sudden market moves because the platform relies primarily on traditional US financial rails and US-based market makers.

Liquidity and trading volume

When it comes to execution volume, Polymarket is the clear leader of the two prediction markets platforms. Driven by global crypto liquidity, non-KYC onboarding for international users, and heavy activity in geopolitical events, it regularly processes billions of dollars in volume. 

That said, Kalshi has experienced exponential volume growth following key regulatory victories and major political events. Today, it leads in liquidity for traditional US sports leagues (e.g. NFL, NBA) and specific economic releases (CPI, Non-Farm Payrolls). 

Fees

Both Kalshi and Polymarket use dynamic, uncertainty-based fee models. Instead of flat percentage fees, they adjust their fees depending on the probability of the event – charging the highest fee at 50/50 odds (maximum uncertainty) and shrinking fees toward zero at high-certainty ends ($0.01 or $0.99). 

For Kalshi, fees for taker orders (orders that match immediately against the book) are charged based on the formula: round up(M x 0.07 x C x P x (1-P)) where P is the price of a contract in dollars (50 cents is 0.5), C is the number of contracts being traded, M is the multiplier for each contract (default is 1 unless otherwise indicated), and round up means it rounds up such that the fee + positionCost is rounded to a centicent.

Maker fees (a maker is someone who places an order that doesn’t execute immediately) are calculated with the following formula: round up(M x 0.0175 x C x P x (1-P)) where P is the price of a contract in dollars (50 cents is 0.5), C is the number of contracts being traded, M is the multiplier for each contract (default is 0 unless otherwise indicated), and round up means it rounds up such that the fee + positionCost is rounded to a centicent. 

Other fees for Kalshi are:

• ACH deposit/withdrawal: Free 
• Debit card deposits: Up to 2% 
• Settlement/expiration fee: Free 

Turning to Polymarket, it charges a taker fee on certain markets. Fees are calculated using the following formula: C × feeRate × p × (1 – p) where C is number of shares traded and p is the price of the shares. feeRate varies by category:

• Crypto: 0.07
• Sports: 0.05
• Finance: 0.04
• Politics: 0.04
• Weather: 0.05
• Geopolitics: 0.00

With Polymarket, maker fees are always $0.00.  

Other fees are:

• On-chain transactions: No native trading gas fees (handled via Polygon relayers), though standard network gas fees apply when initiating Web3 wallet transfers/withdrawals.
• Fiat-to-crypto onramps: Third-party payment gateways (credit card/bank to USDC) charge standard processing fees (typically 1%–3%).

Institutional footprint and white-label solutions

Kalshi is leading the institutional and white-label integration race in the US today. Because it holds a CFTC DCM license, traditional brokerage firms can embed its order matching engine directly into their own platforms.

One well-known company that uses Kalshi for prediction markets is Robinhood. Another is Coinbase. 

It’s worth noting that media organisations and financial data terminals frequently reference Polymarket odds. However, its lack of direct US exchange status limits its ability to white-label trading services inside mainstream US brokerages.

Kalshi & Polymarket versus CME & CBOE event contracts

Traditional derivatives exchanges like the Chicago Mercantile Exchange (CME) and Chicago Board Options Exchange (CBOE) also offer event-based contracts. However, these products differ in a number of ways to those offered by Kalshi and Polymarket:

• Accessibility: Accessing CME/CBOE event contracts requires an account with a participating regulated broker or Futures Commission Merchant (FCM) such as Interactive Brokers or Charles Schwab. By contrast, Kalshi and Polymarket offer frictionless, direct-to-exchange onboarding.
• Contract design: While Kalshi and Polymarket list thousands of different events – ranging from Fed rate cuts to pop culture and election margins – CME event contracts are derivative instruments tied strictly to established benchmark futures (e.g. S&P 500, WTI crude, gold). 
• Fees: CME contracts incur exchange fees, clearing fees, and FCM commissions, making micro-trading ($1–$100 trades) inefficient. Kalshi and Polymarket, however, are built specifically for micro-contract sizing with low transaction costs.

Summary: What is the best platform for US traders?

For US traders, Kalshi is the best platform for a number of reasons, including regulatory compliance, platform integration, and USD simplicity. Its embedded presence on platforms like Robinhood makes it a safe and accessible venue for American traders.

However, Polymarket remains the global benchmark for liquidity, tight spreads, and market diversity. While regulatory issues limit direct US participation on its main platform, its deep order books are hard to ignore.