Polymarket vs Kalshi: Complete Comparison for Arbitrage Traders (2026)

TL;DR

Polymarket and Kalshi often price the same events differently, creating arbitrage opportunities averaging 4-7% ROI. ArbBets scans 990+ markets daily and finds 70-100 profitable opportunities. Example: LA Mayoral election currently offers 7.53% guaranteed profit by buying Yes on Kalshi (58¢) and No on Polymarket (35¢). Polymarket offers higher liquidity and more markets but is unregulated, while Kalshi is CFTC-regulated and fully legal for US residents.

Polymarket vs Kalshi: Quick Comparison

What is Polymarket?

Polymarket is a decentralized prediction market built on the Polygon blockchain. Users trade event contracts using USDC (a stablecoin pegged to USD). The platform has become the largest prediction market by volume, regularly exceeding $1 billion in monthly trading during major events like elections.

Polymarket Strengths

• High liquidity: Deep order books mean large trades execute with minimal slippage
• Zero trading fees: No fees on trades (only blockchain gas fees)
• Wide market selection: 1,000+ markets covering politics, crypto, sports, entertainment
• Fast settlement: Markets resolve within hours of event completion
• No position limits: Trade as much as you want

Polymarket Limitations

• US access restricted: Not legally available to US residents without VPN
• Crypto-only: Requires USDC deposits via crypto wallet
• Unregulated: No regulatory protection if disputes arise
• Withdrawal complexity: Requires crypto knowledge to cash out

What is Kalshi?

Kalshi is the first CFTC-regulated prediction market exchange in the United States. It operates as a Designated Contract Market (DCM), meaning it follows the same regulatory standards as major futures exchanges like CME.

Kalshi Strengths

• Fully regulated: CFTC oversight provides legal protection and legitimacy
• US legal: The only prediction market legally available to all US residents
• Easy deposits: Bank transfers and debit cards accepted
• USD settlement: No crypto required—trade and withdraw in dollars
• Mobile app: Native iOS and Android apps for trading

Kalshi Limitations

• Position limits: Maximum positions typically $25,000-$100,000 per market
• Trading fees: 0-1% fee per contract (recently reduced)
• Lower liquidity: Smaller order books than Polymarket
• Fewer markets: ~500 markets vs Polymarket's 1,000+

Why Price Differences Create Arbitrage Opportunities

Polymarket and Kalshi attract different user bases with different information and biases. This creates persistent price discrepancies:

1. US vs International traders: Kalshi users are US-only, while Polymarket attracts global traders
2. Crypto vs traditional finance: Polymarket's crypto-native users may have different risk tolerances
3. Liquidity differences: Lower liquidity on Kalshi means prices adjust slower
4. Information asymmetry: Breaking news reaches platforms at different speeds

These factors mean the same event often trades at different prices, creating risk-free profit opportunities.

How Polymarket vs Kalshi Arbitrage Works

When the same event trades at different prices on Polymarket and Kalshi, you can lock in guaranteed profit by betting both sides:

Example: LA Mayoral Election

Total cost: 58¢ + 35¢ = 93¢

Guaranteed payout: $1.00 (one contract always pays out)

Profit: 7¢ per dollar wagered = 7.53% ROI

This works because you own both outcomes. If Karen Bass wins, your Kalshi Yes contract pays $1. If she loses, your Polymarket No contract pays $1. Either way, you profit 7 cents on every 93 cents invested.

Current Arbitrage Opportunities

Opportunities update in real-time. Check ArbBets for current prices.

Which Platform Should You Choose?

Choose Polymarket If:

• You're outside the US or comfortable using VPN
• You want the highest liquidity and most markets
• You're already familiar with crypto and USDC
• You want to trade large positions without limits
• Zero trading fees matter to you

Choose Kalshi If:

• You're a US resident wanting legal access
• You prefer trading in USD with bank deposits
• Regulatory protection is important to you
• You want a mobile app for trading
• You're new to prediction markets

Use Both for Arbitrage:

• Access to both platforms doubles your arbitrage opportunities
• Price differences between platforms create the most profitable arbs
• Different market selection means more total opportunities

Arbitrage Considerations

Execution Speed

• Prices can change while you place orders
• Having accounts funded on both platforms is essential
• Use limit orders when possible to guarantee prices

Capital Requirements

• Need funds on multiple platforms simultaneously
• Typical arb opportunities require $100-$1,000 to be worthwhile
• Factor in withdrawal times when planning

Fee Impact

• Polymarket: 0% trading fees (only gas)
• Kalshi: 0-1% fees reduce profit margins
• Always calculate net profit after all fees

Frequently Asked Questions

Is prediction market arbitrage legal?

Yes. Trading on regulated platforms like Kalshi is fully legal for US residents. Arbitrage itself is a standard trading strategy used across all financial markets.

How much money do I need to start?

You can start with as little as $100-$500 split across platforms. Larger bankrolls allow you to capture more opportunities and generate meaningful profits.

How often do arbitrage opportunities appear?

ArbBets typically finds 70-100 opportunities daily across Polymarket, Kalshi, and Opinion. Most offer 3-7% ROI with some reaching 10%+.

Can I lose money on arbitrage?

Pure arbitrage is risk-free by definition—you're guaranteed profit regardless of outcome. However, execution risk exists if prices move before you complete both trades.

Start Finding Arbitrage Opportunities

Manual arbitrage hunting is time-consuming and you'll miss most opportunities. ArbBets scans 990+ markets across Polymarket, Kalshi, and Opinion in real-time, alerting you to profitable opportunities as they appear.