Kalshi vs Polymarket
Kalshi and Polymarket side by side from official sources: who regulates each, how fees work, what the APIs offer and where you’re allowed to trade. We don’t pick a winner; what fits depends on where you live and what you trade.
Checked · every row links its source
| Kalshi | Polymarket | |
|---|---|---|
| Operator | KalshiEX LLC | QCX LLC d/b/a Polymarket US (US exchange). The international order book is a separate product with its own docs. Source: docs.polymarket.com |
| US regulation | CFTC designated contract market (DCM) since Nov 4, 2020. Source: cftc.gov/PressRoom/PressReleases/8302-20 | Polymarket US: CFTC designated contract market (DCM), designated Jul 9, 2025. On Nov 24, 2025 the CFTC amended the order to allow futures commission merchants to carry customer accounts. Source: cftc.gov/IndustryOversight/IndustryFilings/TradingOrganizations/4957 |
| Regulator actions on record | Mar 4, 2025: Nevada's Gaming Control Board ordered KalshiEX to stop offering sports and election event contracts in Nevada, treating them as unlicensed wagering. Source: gaming.nv.gov/siteassets/content/about/press-release/NGCB_-_News_Release_ | Jan 3, 2022: per the CFTC, Blockratize Inc. d/b/a Polymarket settled charges of offering unregistered off-exchange event-based binary options; $1.4M penalty and wind-down of non-compliant markets. Source: cftc.gov/PressRoom/PressReleases/8478-22 |
| Trading fees | Taker fee on most markets: round up(M × 0.07 × C × P × (1 − P)), where C is contracts, P is the price in dollars and M is the market’s multiplier (usually 1). At 50¢, 100 contracts cost $1.75 in fees. Resting (maker) orders pay nothing unless the market lists maker fees, and canceling a resting order is free. Source: kalshi.com/docs/kalshi-fee-schedule.pdf Source: help.kalshi.com/en/articles/13823805-fees | Taker fee = C × feeRate × p × (1 − p), with the rate set per category (for example 0.07 for crypto, 0.05 for sports, 0.04 for politics, 0 for geopolitics). Makers are never charged fees. No Polymarket fee to deposit or withdraw. Source: docs.polymarket.com/trading/fees.md |
| Where you can trade | Not verified yet: we haven’t checked Kalshi’s state-by-state eligibility, so read its terms. For Nevada, see the regulator action above. | Polymarket’s international order book rejects orders from restricted locations. The United States, the United Kingdom, France, Germany, Australia and several Canadian provinces, among others, are close-only on both the website and the API: you can close positions but not open new ones. Iran, Syria, Cuba, North Korea and occupied regions of Ukraine are blocked completely. Source: docs.polymarket.com/api-reference/geoblock.md |
| Trading API | Kalshi’s official Exchange API covers real-time market data and trade execution over REST, WebSocket and FIX. Using it binds you to Kalshi’s Developer Agreement. Source: docs.kalshi.com/welcome Kalshi runs a separate demo environment with mock funds for testing; credentials are not shared with production, and Kalshi warns that demo prices may not reflect real markets. Source: docs.kalshi.com/getting_started/demo_env.md | Polymarket publishes REST and WebSocket APIs: the CLOB API reads prices and order books and places and manages orders; the Gamma and Data APIs cover market discovery and activity. Source: docs.polymarket.com/getting-started/api.md Polymarket’s docs include a market-making guide, and resting limit orders are automatically eligible for its Liquidity Rewards program. Source: docs.polymarket.com/programs/liquidity-rewards.md |
| How your bot signs in | API keys are key pairs (Ed25519 or RSA): your program signs each request with the private key and Kalshi checks it against the registered public key. Source: docs.kalshi.com/getting_started/api_keys.md | Orders are signed by your own wallet. To trade, the wallet needs pUSD on Polygon and trading approvals for Polymarket’s contracts. Source: docs.polymarket.com/trading/market-making.md |
| API limits | Requests spend tokens from a per-account budget (most cost 10 tokens). The Basic tier, which every account gets at signup, refills 200 read and 100 write tokens per second; higher tiers are earned by trading volume or assigned by Kalshi. Source: docs.kalshi.com/getting_started/rate_limits | Not verified yet: we haven’t checked Polymarket’s current API rate limits. |
| API report card | Caution Kalshi API fact sheet At least one documented security incident, regulator action (non-fraud) or unverified performance claim in the last 5 years. | Caution Polymarket API fact sheet At least one documented security incident, regulator action (non-fraud) or unverified performance claim in the last 5 years. |
| Bots in our directory that list it | Kalshi AI Trading Bot, pmxt, CloddsBot, Prediction Markets Trading Bot Toolkits, Oracle3 prediction market agent | NautilusTrader, Lumibot, poly-maker, OctoBot Prediction Market, pmxt, CloddsBot, Nothing Ever Happens (Polymarket bot), Prediction Markets Trading Bot Toolkits, Oracle3 prediction market agent |
Facts checked Oct 20, 2026 on the linked official pages; venue status from CFTC records (checked Oct 15, 2026). Report cards follow published rules and cover the official APIs, not your odds of winning. Event contracts can lose your whole stake. Not investment, legal or tax advice.
Frequently asked questions
Is Kalshi legit?
Kalshi is run by KalshiEX LLC, which has been a CFTC designated contract market (DCM) since Nov 4, 2020. Mar 4, 2025: Nevada's Gaming Control Board ordered KalshiEX to stop offering sports and election event contracts in Nevada, treating them as unlicensed wagering. CFTC designation means the exchange is regulated; it doesn’t make any trade safe or profitable.
Is Polymarket legit?
Polymarket US (QCX LLC d/b/a Polymarket US) has been a CFTC designated contract market since Jul 9, 2025. Its international order book is a separate product. Jan 3, 2022: per the CFTC, Blockratize Inc. d/b/a Polymarket settled charges of offering unregistered off-exchange event-based binary options; $1.4M penalty and wind-down of non-compliant markets.
Is Polymarket available in the US?
Not the international order book: Polymarket’s own docs list the United States as close-only on both the website and the API (you can close positions but not open new ones). US users are pointed to Polymarket US, a separate CFTC-designated exchange with its own docs.
Kalshi vs Polymarket fees: how do they compare?
Both charge takers a fee shaped like price × (1 − price), so it peaks at 50¢. Kalshi: Taker fee on most markets: round up(M × 0.07 × C × P × (1 − P)), where C is contracts, P is the price in dollars and M is the market’s multiplier (usually 1). Polymarket: Taker fee = C × feeRate × p × (1 − p), with the rate set per category (for example 0.07 for crypto, 0.05 for sports, 0.04 for politics, 0 for geopolitics). Polymarket makers are never charged; Kalshi makers pay only on markets that list maker fees. Check each market’s current rate before you trade.
Can I use a trading bot on Kalshi or Polymarket?
Both publish official trading APIs, so automated trading itself is supported. Kalshi’s API runs under its Developer Agreement and has a demo environment with mock funds; Polymarket orders are signed by your own wallet. See our guide to Kalshi and Polymarket trading bots.
Related
- Kalshi & Polymarket trading bots: allowed, legit, and what to check
- Kalshi API vs Polymarket API: the developer fact sheets side by side
- All 13 prediction-market bots and tools with report cards
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