GUIDE · UPDATED 2026-10-17
Polymarket vs Kalshi (2026): Fees, Regulation, Access and Which Fits You
30-second answer: pick Kalshi if you're US-based, want dollars in and out through banks, and value a single CFTC-regulated venue. Pick Polymarket if you're crypto-comfortable and want the widest catalog at zero trading fees on the global exchange — or the regulated Polymarket US app if you're American and prefer its fee formula. Both are legitimate; they differ on custody, fees, breadth and settlement machinery.
The comparison table
| Kalshi | Polymarket (global) | Polymarket US | |
|---|---|---|---|
| Regulation | CFTC DCM | Offshore crypto venue | CFTC DCM (QCX LLC) |
| US access | Yes, nationwide (sports contested in states) | No — US persons excluded | Yes, app + web with KYC |
| Deposits | USD bank transfer, card (≤2% fee) | USDC on-chain | Funding via app |
| Trading fee | 0.07×C×P×(1−P) | 0% | 0.0695×C×P×(1−P) |
| Fee on 100 @ 50¢ | $1.75 | $0.00 | ≈$1.00 |
| Custody | Intermediated (cash account) | Self-custody wallet (USDC) | Intermediated |
| Settlement | Exchange rulebook, automatic cash | UMA optimistic oracle (disputable) | Exchange rulebook |
| Catalog | Macro, politics, sports, weather, crypto | Largest catalog overall | Curated, growing |
Choose by situation
- "I just want to trade the Fed decision in dollars." Kalshi — cash account, automatic settlement, macro catalog is its home turf.
- "I want the most markets and I already hold USDC." Polymarket global — zero fees and unmatched breadth, accepting oracle-dispute risk.
- "I'm in the US and want Polymarket's style legally." Polymarket US — regulated venue, slightly cheaper taker formula than Kalshi, smaller catalog.
- "I trade sports." Check your state first: Kalshi's sports contracts face state challenges, Robinhood offers an in-app alternative in eligible states, and availability is changing quarter to quarter (legal tracker).
- "I care about settlement certainty." Both regulated venues pay per rulebook automatically; the global Polymarket exchange can, in rare disputed cases, resolve late or against the initial read.
Fee math worth knowing before you pick
The two fee formulas are nearly twins — Kalshi at 0.07, Polymarket US at 0.0695 — so venue choice rarely swings on the fee itself. What moves real P&L: card-deposit surcharges, on-chain withdrawal costs for USDC, and spreads on thin markets. On a 5¢ longshot, both formulas cost roughly a third of your stake per side — which is why professionals trade small edges on liquid, mid-priced contracts and treat lottery tickets as entertainment. The mechanics behind the formulas are in how prediction markets work.
What they share (so you can stop worrying)
Both display prices as implied probability, both let you exit before resolution, both document resolution sources per market, and both keep full trade histories you can export for taxes. US-taxable users should expect documentation from the regulated venues; self-directed crypto trading requires better record-keeping on your side.
Is one safer than the other?
Different risk profiles: Kalshi concentrates counterparty risk in a US-regulated clearinghouse; Polymarket global puts custody in your wallet but settlement risk in an oracle. Polymarket US splits the difference. None of them eliminates market risk — you can still simply be wrong.Can I use both?
Yes, and many traders do: hedge or arbitrage across venues when prices diverge, keeping in mind US persons may only use the US-regulated venues, and cross-venue transfers take time.Independent comparison — no affiliate relationship with any platform named. Educational content, not financial, legal or tax advice. Fees and status verified October 2026 from published schedules and CFTC filings.
We compared regulation, fees, custody and market breadth across the big four.