Kalshi Hub

What Kalshi Is

Kalshi is a US event-contract exchange. Traders buy and sell binary Yes/No contracts on the outcome of a defined real-world event — a Federal Reserve decision, an inflation print, an election result, a temperature reading in a named city. A Yes contract that resolves correct pays out $1.00 and one that resolves incorrect pays $0.00, so the traded price of a contract reads directly as the market's implied probability.

What separates Kalshi from most prediction markets is its regulatory status. Kalshi is regulated by the Commodity Futures Trading Commission (CFTC) as a Designated Contract Market (DCM) — the same regulatory category used for US futures exchanges. Its own documentation states that it operates as a neutral exchange that takes no financial position in the outcomes it lists, and that its revenue comes from transaction fees rather than from the other side of a trade.

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The Structure in One Table

International funding, eligibility and fee mechanics above are taken from Kalshi's published help-centre documentation. Fee amounts vary by market — always confirm the fee shown in the order ticket before you trade.

How Kalshi Differs From Polymarket

The two platforms reach prediction markets from opposite directions. Polymarket is a decentralised, non-custodial market on the Polygon blockchain settled in USDC, with no account registration for standard trading — and it restricted US users after a CFTC settlement. Kalshi is a registered US exchange settled in USD through the conventional financial system, open to US residents and to traders in many other countries under its Member Agreement.

That single structural difference cascades into everything else: how you fund an account, whether identity verification is required, how a market resolves, and what recourse exists if you disagree with a resolution. Our full comparison is in Kalshi vs Polymarket, with the trader-profile verdict in the wiki's platform comparison.

Tools on This Site

Nothing on poly-sim.com places trades. These tools help you evaluate a market before you commit capital, on either platform:

• Cross-Platform Edge Calculator — subtract both platforms' fee structures from a quoted price gap and see whether any edge survives.
• Kelly Criterion Calculator — size a position from your own probability estimate and the price you can actually get.
• Expected Value Calculator — convert a probability estimate and a price into per-dollar EV.
• Poly-Sim Score — rate any open Polymarket contract by information-adjusted return.
• Daily Edge — the markets the model currently rates as most mispriced, refreshed through the day.

How a Kalshi Price Becomes a Probability

Kalshi's documentation states the constraint that makes the whole market legible: the combined investment of the buyer of Yes and the buyer of No must equal $1.00. That single rule is what turns a contract price into a probability reading. If the Yes contract trades at 70¢, the market is saying it believes there is a 70% chance the event happens — and the No contract is priced at 30¢.

Two properties follow directly from the $1.00 constraint, and both shape how you trade. First, the maximum loss on a long position is the price you paid — a contract bought at 12¢ can lose 12¢, not more. Second, the maximum gain is the distance to $1.00 — that same 12¢ contract pays 88¢ if it resolves correct. This is the identical payoff geometry to a Polymarket position, reached through a different settlement rail.

Price discovery comes from order matching, not from the exchange setting a price. Kalshi pairs a trader wanting Yes with a trader wanting No, which is why quoted spreads and available depth vary market by market. For why that matters to execution, see liquidity and spread.

What Kalshi Actually Lists

Kalshi's breadth is narrower than Polymarket's and deeper inside the families it covers, because each new contract type has to fit inside its regulated framework. The recurring families are recognisable:

The families above are described in general terms only. The authoritative wording, the exact threshold and the named verification source for any single contract live in that market's own rules summary — confirm them there, in the market you are actually trading, before you commit capital.

Five Mistakes New Kalshi Traders Make

1. Assuming the market closes when the event happens. Kalshi documents two distinct closure types — closure when the outcome occurs, and closure at a listed date and time. A scheduled-close market can keep trading after the news is already public, which changes the risk of holding into the close. The type is stated in the market's Timeline and Payout section.
2. Carrying a fee assumption from one market to the next. Kalshi states that some markets carry fees that differ from others, and that some carry maker fees. A rate learned on one contract is not a rate you can rely on for the next. See Kalshi Fees Explained.
3. Skimming the rules summary. Whether a market counts a rate cut rather than a change, whether it measures a percentage or an absolute figure, and which agency's release settles it are all defined in writing. These are the terms that decide whether a correct read of the world actually pays.
4. Reading a low price as a bargain. A contract at 5¢ is not a discount — it is the market saying there is a 5% chance. It is cheap because it is unlikely to pay, and the expected value is negative unless your own estimate is materially above the market's.
5. Ignoring resolution latency. Kalshi's documentation states determination can take anywhere from one hour to more than twelve hours after closure. If you are rotating capital between positions, that window is a real cost of the strategy, not a rounding error.

Using Both Platforms Without Confusing Them

Most readers of this hub arrive with a Polymarket habit and a Kalshi question, or the reverse. The two venues share one instrument — a binary contract priced as a probability — and differ on almost everything around it: custody, currency, identity verification, breadth and fee basis.

Four pages on this site cover the overlap, in the order that answers the most common questions first:

• Kalshi vs Polymarket — structure, custody, funding, fee mechanics and a verdict by trader profile.
• Polymarket vs Kalshi on the wiki — the same comparison from the Polymarket side, including US access and regulation.
• Cross-Platform Edge Calculator — model whether a price gap between the two survives both fee bases, and run the four-key contract identity check first.
• Prediction market arbitrage — how cross-venue arbitrage works in theory and the practical obstacles that kill most of it.

If you are new to the instrument itself rather than to Kalshi, start with how a prediction market works and implied probability, then size any resulting position with the Kelly calculator rather than by intuition.