Kalshi vs Polymarket: Which Should You Use?
CFTC-regulated vs crypto-native — the real differences in fees, selection, legality, and execution.
The Core Difference: Regulation vs Reach
Kalshi is a CFTC-regulated exchange headquartered in New York. Every contract it lists has been reviewed by federal regulators, funds are held with US banks, and US residents can sign up with a driver's license and a bank account in ten minutes. Polymarket is a crypto-native decentralized market running on Polygon that settles in USDC, serves a global audience, and historically lists a much wider variety of contracts because it doesn't need contract-by-contract regulatory approval.
This single fact drives almost every downstream difference — market selection, fees, withdrawal speed, and, crucially for American traders, whether you can legally use the platform at all.
US Legality in 2025
If you live in the United States, Kalshi is the straightforward choice: it's explicitly legal, it files 1099s, and it operates like any other regulated brokerage. The CFTC approved Kalshi's event contracts, and its election markets went live in late 2024 after a federal court ruling.
Polymarket is officially unavailable to US persons and enforces geofencing. Many US traders historically accessed it via VPN and self-custodied wallets, but that's a gray area and the platform will close accounts it detects. If you're in the US and want a no-headache experience, start with Kalshi. If you're international, Polymarket's depth usually wins.
Market Selection and Depth
Polymarket lists more contracts by a wide margin — thousands of active markets across politics, crypto, sports, entertainment, science, and meme-tier cultural bets. Because listings don't require regulator sign-off, Polymarket ships niche markets fast (think 'Will a specific tweet happen this week').
Kalshi is narrower but deeper on the contracts it does list. Economic indicators (CPI, Fed decisions, unemployment), weather, elections, and a rapidly expanding sports catalog all have serious liquidity — often tighter spreads than Polymarket on the same question. For macro and sports, Kalshi is frequently the better venue.
Fees, Spreads, and Real Execution Cost
Polymarket is zero-commission at the protocol level — you pay only the bid-ask spread and a tiny Polygon gas fee. On liquid markets, spreads are often 1¢ or less, which makes it one of the cheapest ways to express a view on the planet.
Kalshi historically charged a per-contract fee that scales with the trade's risk, but has moved to a low-flat-fee model on many markets. For small positions the cost is negligible; for very large positions Polymarket usually wins on net-of-fee execution. Always compare the effective mid-price on both venues before placing a trade, especially on popular events listed on both.
Withdrawals, Deposits, and Cash Flow
Kalshi wins decisively on banking. Deposits are ACH or wire from your US bank; withdrawals land in 1–3 business days with no crypto complexity. For most American retail traders, this alone makes Kalshi worth using.
Polymarket deposits and withdrawals happen in USDC on Polygon. Once you're comfortable with a wallet, it's actually faster than ACH — withdrawals clear in seconds on-chain. But you'll need to bridge USDC back to fiat through a centralized exchange, which adds a step and a KYC trail.
Who Should Use Which
Pick Kalshi if: you live in the US, you want a tax-reportable clean experience, your focus is macro indicators, weather, or sports, and you value trust over breadth. Pick Polymarket if: you live outside the US, you're comfortable holding USDC, you want the widest possible selection of political and cultural markets, or you need deep liquidity on headline events like elections and major sports finals.
Many serious traders use both. The same question — say, 'Will the Fed cut rates in June?' — often has slightly different prices on each venue. That spread is an arbitrage opportunity, and even without arbing it, you can just take whichever side is cheaper on whichever platform.
How Polykit Supports Both
Polykit's Analyzer accepts screenshots from either Polymarket or Kalshi. Our vision model reads the contract title, YES/NO price, volume, and deadline, then runs the same news-grounded pricing engine regardless of venue. The output is identical: fair value estimate, directional recommendation, written reasoning, and a risk score.
This means you can shop the same thesis across both markets and take the better price. Our Wallet Tracker surfaces sharp Polymarket addresses, while Kalshi's closed data model means we focus on volume and price-action signals there. Bottom line: one subscription, two venues, one workflow.