Kalshi vs Polymarket (2026): Fees, Markets, and Which to Use

This comparison covers late August 2026, plus a third platform, Totalis, built for the multi-leg positions both giants added in the past year.

Quick comparison#

Kalshi#

Kalshi is a federally regulated exchange for event contracts. Every market is a Yes/No question. Contracts trade between 1 and 99 cents and settle at $1.00 if the event happens, so a 60-cent contract means the market says 60%.

Kalshi received its CFTC designation in November 2020 and opened publicly in 2021, the first CFTC-regulated exchange dedicated to event contracts. Everything runs in dollars: you fund by bank transfer, card, wire, real-time payments, PayPal, Venmo, Cash App or crypto, with crypto converted to dollars for US users. No wallet, no gas.

Sports has been roughly 85% of Kalshi's volume since it launched sports contracts in January 2025, and it is Kalshi's legal battleground: regulators in a dozen or more states contest whether sports event contracts count as gambling. In late 2025 Kalshi opened to 140+ more countries, with some jurisdictions, including the UK, excluded. In 2026 it launched the first CFTC-regulated perpetual futures for US traders and raised $1 billion at a $22 billion valuation.

Fees. On most markets takers pay roughly 0.07 x price x (1 - price) per contract, about 1.75 cents on a 50-cent contract and less toward the extremes. Some markets use a different multiplier; the exact figures are in the fee schedule. Makers on combos traded free until Kalshi began charging them in August 2026, with independent NFL-only combos exempt.

Polymarket#

Polymarket launched in 2020 and became the reference prediction market, the one quoted when a news anchor says "markets give this a 70% chance." It runs an order book, settles in USDC, and covers politics, geopolitics, sports, crypto, culture and finance for an international user base.

Its big change of the past year was coming back to the US. Geo-blocked since a 2022 CFTC settlement, Polymarket acquired QCEX, a CFTC-licensed exchange and clearinghouse, in July 2025, received an amended designation in November, and began rolling out Polymarket US in early December. It now runs two venues: the regulated US platform and the larger international one.

Fees. Polymarket was nearly free for most of its life. On March 30, 2026 it expanded taker fees to most categories on a probability-weighted curve, with multipliers of 0.04 (politics, finance, tech), 0.05 (sports, economics, culture, weather) and 0.07 (crypto). Geopolitics and world events stayed free. Makers pay nothing and earn rebates. Polymarket US uses a separate schedule: a uniform 0.06 taker multiplier on every market, plus a maker rebate.

Totalis#

Totalis is a prediction market platform built around parlays. A position is 2 to 5 event outcomes in one trade. Every leg must hit for it to pay, and the payout multiplies with each leg. The legs reference markets listed on Kalshi and Polymarket, so one Totalis parlay can mix markets from both.

The difference from Kalshi and Polymarket combos is scope. A Totalis position can combine a Bitcoin price level, a Fed decision, an election result and a weather event in one ticket. Market makers quote each combination live, so you see the exact cost and payout before committing. Fees are one structure everywhere: a 1% taker fee on the stake, plus 1% of the winning side's profit at settlement. No curves, no category exceptions.

Settlement is on Solana. A filled parlay is an on-chain position you hold to resolution, and you can ask to exit early through a cashout auction, though a sale is not guaranteed. Totalis came out of Y Combinator's Spring 2026 batch, the first company YC funded entirely in USDC, and launched parlay trading in May 2026. It is months old, without the volume, market count or regulatory footprint of the two giants, and it is not available to US users.

Combos and parlays#

The biggest shift in prediction markets in 2026 is a new shape of trade, not a new venue.

Kalshi launched Combos in late 2025, priced by request for quote: market makers price each bundle individually, and each filled combo becomes its own market. Combo volume went from $4.77 billion in May 2026 to $13.78 billion in July, and during the World Cup combos reached roughly half of Kalshi's total volume. Polymarket rolled out Combos internationally in June 2026 after QCEX self-certified them with the CFTC, then brought them to Polymarket US on August 19 and 20, 2026, with up to 10 legs.

Both products are built for sports. Polymarket's combos are moneyline, spread and totals picks; Kalshi's grew out of same-game parlays and remain sports-centric. They are sportsbook parlays on exchange rails, and they are taking volume from sportsbooks for that reason. (If the words are new, combos and parlays are the same trade.)

Neither is built for a position that spans categories: a hot CPI print, so the Fed holds, so Bitcoin sells off. On the giants that view is three separate contracts, three spreads, three pieces of collateral. On Totalis it is one quote, one stake and one payout.

One caution before trading combos anywhere. An analysis of mid-2025 to March 2026 activity found retail prediction-market users at a median return of about -8% as combos surged. Every leg must hit; a 3-leg position that goes 2-for-3 pays zero. For the pricing and correlation math, see how prediction market parlays work.

Collateral#

Kalshi and Polymarket are fully collateralized venues. On Polymarket, every Yes/No pair is backed by a full dollar locked in its token contracts. Kalshi holds the full cost of every position, and its collateral return nets hedged positions only inside a single event. Each Kalshi combo is a separate market, and neither venue documents netting across a book of combos. A market maker quoting a hundred combos posts collateral for a hundred combos.

Totalis margins each maker's book as one portfolio. It computes the worst-case loss across every outcome state of the whole book and locks collateral for that scenario only. Two parlays that cannot both win do not both post their full payout. Modeled across books of 3 to 5 leg parlays, this cuts required collateral by 30 to 40% against posting each trade alone.

The trader sees this as price. Capital a maker does not have to lock is capital it can quote with, so tighter odds on your parlay.

Fees: which is cheaper?#

Between the giants it depends on category and role:

• Takers. Polymarket is cheaper on most categories. Its 0.04 and 0.05 multipliers come in roughly 30 to 45% under Kalshi's 0.07 at the same price, and geopolitics is free.
• Makers. Polymarket pays every maker a rebate. Kalshi has no universal rebate and now charges makers on combos.
• Sports and economic data. Depth matters more than fee schedules. As of August 2026 Kalshi's books there are deeper, and a tighter spread routinely saves more than the fee difference.

Totalis charges 1% of stake plus 1% of winning profit on every market and every combination. Per contract that can be cheaper or pricier than the giants depending on price. Per position the comparison is simpler: a five-leg view as five contracts is five spreads and five fees. On Totalis it is one.

Liquidity#

Kalshi leads raw volume, about $31.5 billion in June 2026 to Polymarket's $13.3 billion across both platforms, driven by sports and US economic events where institutional participation keeps books tight.

Polymarket owns the categories that made prediction markets famous: elections, geopolitics, world events. As of August 2026 its flagship political markets are among the most liquid in the industry. Crypto is roughly even between the two.

Totalis does not match either giant's depth on any single market. Its makers quote each combination on demand, and for combinations that reference both exchanges' markets across categories it is the only one of the three that prices them.

Funding and custody#

Kalshi is the traditional-rails choice: dollars in, dollars held at a regulated US exchange, dollars out. Polymarket International is crypto-native, with USDC in a wallet you control and positions verifiable on-chain. Polymarket US funds in USD by debit card, ACH or wire under a CFTC-regulated entity.

Totalis is stablecoin-native. Deposits, positions and settlement live on Solana in non-custodial vaults. Kalshi and Polymarket US carry CFTC oversight that no on-chain venue currently replicates. If regulatory protection is your first filter, the US-regulated platforms win. Totalis is not available to US users.

Which should you use?#

Kalshi if you want dollar-native, regulated trading, your focus is sports or US economic data, or you want the deepest sports combo product.

Polymarket if you trade politics, geopolitics or world events, you make markets and want rebates, or you are outside the US on crypto rails.

Totalis if you are outside the US and your view spans categories rather than one question or one sport, and you want one position instead of a stack of tickets. Build a parlay on Totalis.

For most active event traders the answer is a stack, not a pick: single-event depth where each giant is strongest, sports combos where the books are deepest, cross-category parlays where they exist.

FAQ#

Is Kalshi or Polymarket bigger?#

Kalshi by volume: roughly $31.5B to Polymarket's $13.3B in June 2026, driven largely by sports. Polymarket leads politics and world events and has the larger international footprint.

Is Polymarket legal in the US?#

Yes. After acquiring the CFTC-licensed exchange QCEX in 2025, Polymarket began rolling out its regulated US app in December 2025. The larger international platform is separate.

Which has lower fees?#

For takers, Polymarket on most categories, and geopolitics is free there. For makers, Polymarket pays rebates and Kalshi has no universal one. Totalis charges 1% of stake plus 1% of winning profit everywhere, with no curve and no category exceptions.

Can you parlay on Kalshi or Polymarket?#

Yes, on sports. Kalshi launched Combos in late 2025 and Polymarket added them in 2026, including in the US from August 20, 2026. Parlays that combine politics, sports, crypto, finance, economics, entertainment, weather and tech in one position are Totalis's core product, outside the US only.

How does collateral differ across the three?#

Kalshi and Polymarket hold full collateral against every position, with Kalshi netting hedges only within one event. Totalis margins each market maker's book as a portfolio, which its modeling puts at 30 to 40% less collateral than posting each parlay alone. That freed capital is what lets makers quote tighter.

Are prediction markets bigger than sports betting?#

By monthly volume, the top two combined are: about $45B in June 2026, against a roughly $14B monthly average for state-regulated US sportsbooks in 2025 ($166.9B for the year, per the American Gaming Association).