Is a Kalshi price the probability of the event?

It can be interpreted as a market-implied probability under the contract's stated binary payout assumptions, but it is not a calibrated forecast or assurance of the outcome.

Does a limit or market order always fill?

No. Kalshi's help center says limit order fills are not guaranteed, and any order may fill partially, stay unfilled, or be rejected depending on the book, product, and order constraints.

Is depth the same as volume?

No. Depth is quantity resting near the best prices at one moment; volume is past trading. Neither guarantees you can exit later at a given price.

Does post-only guarantee a rebate or no fee?

No. Post-only expresses the intent to add liquidity. Kalshi's fees page describes maker fees on some markets, so check the fee quote for the specific order.

What is the difference between close, determination, and settlement?

Close is when trading stops, determination is the outcome decision under the market's rules, and settlement is payout under those rules, including any exception or non-binary terms. Timing is rule-specific.

What is the difference between a DCM and a DCO?

A DCM is a CFTC-designated exchange where contracts trade; a DCO is a separate CFTC-registered clearing organization that clears and settles transactions, including netting and managing counterparty credit risk. Neither label is a blanket legality assurance or a guarantee of any customer's funds, and this is not legal advice.

Which tax forms will I get from Kalshi?

Kalshi's tax documentation article lists forms such as 1099-INT, 1099-MISC, and 1099-B/1099-DA for crypto activity where applicable, plus monthly P&L statements, and says it is not tax advice. Ask a tax professional how your activity is treated.

Do these definitions apply to Polymarket?

Not automatically. This page is Kalshi-focused; see the separate Polymarket glossary on polymarket.health for product-specific terms.

Kalshi Glossary: Source-Checked Terms

On Kalshi, a contract's price is a market-implied number set by current orders, not a calibrated forecast. Whether an order fills, what it costs, and how a market settles depend on the current order book, the applicable fee schedule, your order settings, and that market's own rules. The definitions below are independent summaries of Kalshi's help center and API docs as reviewed October 28, 2026; they are not legal, tax, or investment advice.

How to use this glossary

Definitions here are independent summaries scoped to Kalshi, checked against Kalshi's help center, API documentation, and the CFTC's designation announcement (sources reviewed October 28, 2026). Where a term depends on a specific market, the answer is in that market's rules, not here. Examples are hypothetical and not investment advice. To apply these terms to one contract, use our contract evaluation and liquidity worksheet; for cost math, the Kalshi fees guide. Polymarket terms differ by product; see the separate Polymarket glossary on polymarket.health rather than applying these definitions to it.

Contracts, quantities, and value

Event contract — a contract on a stated real-world outcome. Many Kalshi markets are YES/NO and a contract pays $1 if its side is correct under the market's rules; some markets have non-binary or exception payouts defined in their rules, so do not assume $1/$0 in every case.
Contract quantity — the number of contracts you hold or order. It is not a dollar amount.
Paid cost — what you actually spent to open a position: executed price times quantity, plus any fees charged.
Current value — an estimate of what the position is worth now. It depends on which price is used and is not cash you are guaranteed to receive.
Maximum payout — quantity times the contract's stated payout if your side wins (for example, 100 hypothetical YES contracts paying $1 each have a $100 maximum payout). Always label which convention a 'notional' figure uses: entry cost or maximum payout.
Position — your open holding in one market, by side and quantity.

Order book and pricing

Order book — resting orders at each price. Kalshi's API order-book response lists YES bids and NO bids only; the implied ask on one side is $1 minus the best bid on the opposite side. Prices can be expressed in fixed-point dollar strings that may include sub-penny precision, so a universal 1-cent minimum tick should not be assumed.
Implied price — the price as a market-implied number between $0 and $1 under the contract's payout terms. It is not a calibrated or objective probability of the event.
Spread — the gap between the best bid and the best implied ask at one moment.
Depth — quantity resting at or near the best prices at one timestamp. Depth is not the same as historical volume, and neither guarantees you can exit later.
Volume — contracts traded over a past period. It describes history, not current executable quantity.
Midpoint mark — a value halfway between bid and ask, used as an indicative estimate. It is not an executable price, and P&L based on it is not what a trade would return after spread and fees.
Slippage — the difference between the price you expected and the price(s) you actually filled at; it depends on the current book, your quantity, and your order constraints.

Order types and settings

Limit order — an order at a set price or better. Per Kalshi's help center, a fill is not guaranteed; it may fill fully, partially, or not at all.
Market order (general term) — an order intended to trade against current resting orders. Depending on the book, product, and order constraints it might fill partially, remain unfilled, or be rejected; it is not an execution promise.
Maker / taker — a maker order rests on the book and adds liquidity; a taker order trades against a resting order. Kalshi's fees page describes maker fees on some markets and differences by market, so maker status does not by itself mean a zero fee.
Time in force (API) — Kalshi's Create Order API documents fill_or_kill (fill entirely or cancel), immediate_or_cancel (fill what is available, cancel the rest), and good_till_canceled. These are API fields; this guide does not promise which options the app shows.
Post-only (API) — a post_only flag expressing the intention that the order only rest and add liquidity rather than take. It is not a guaranteed rebate or fee exemption.
Resting, canceled, executed — order states returned by the API. A canceled order can still have earlier partial fills, so check fills, not just status.

Close, determination, and settlement

Close — when trading on a market stops, per its rules. Close time can differ from when the outcome is known.
Resolution source — the source and criteria named in the market's rules for deciding the outcome.
Determination — the decision of the outcome under those rules; timing is rule-specific and may follow source publication or review.
Settlement — payout of positions after determination, according to the market's rules, including any exception or non-binary payout terms. This guide does not promise instant cash.

Regulatory, account, and tax terms

CFTC — the US Commodity Futures Trading Commission. On November 4, 2020 the CFTC announced it had designated KalshiEX as a Designated Contract Market (see the CFTC release in Sources below).
DCM — Designated Contract Market, a CFTC-designated exchange where contracts trade. Designation is not a blanket statement that every contract or every person's participation is legal everywhere.
DCO — Derivatives Clearing Organization. The CFTC describes clearing organizations as entities that clear and settle transactions, including netting and managing credit risk between counterparties, and that must register with the CFTC. It is a role distinct from a DCM; this glossary does not describe it as a guarantee of any customer's funds.
Eligibility and identity verification — Kalshi's sign-up article describes identity checks and states that individuals are responsible for knowing whether participation is legal where they are, with international restrictions. Verification requirements are set by Kalshi and are not a guarantee that any funding method or account will be approved.
Tax documents — Kalshi's tax documentation article lists forms such as 1099-INT, 1099-MISC, and 1099-B/1099-DA for crypto activity where applicable (not all trading), plus monthly P&L statements, and says it is not tax advice. Which forms apply and how any contract is taxed is a question for a tax professional; this guide makes no Section 1256 or other treatment claim.

Term-to-check list before an order

Independent guidance: record each item at one stated time, keep unknowns marked unknown, and keep the record yourself. This checklist does not submit orders or collect account details; keep the record yourself. For fee quotes see the Kalshi fees guide; if an order result is uncertain, do not resubmit and use the troubleshooting decision checklist.

Market name and ticker.
Rule source, close time, and determination criteria and timing from the market's rules.
Order settings: limit price, quantity, and time in force.
Visible depth at your price, with the timestamp you saw it.
Fee quote shown for this order.
After submitting: fill status, filled quantity, and remaining quantity. If the result is uncertain, do not resubmit until you reconcile it.

Sources reviewed October 28, 2026

Limit orders; Fees; Market rules; Market FAQs; Signing up as an individual; Tax documentation; Create Order API; Order book responses; CFTC DCM designation; CFTC clearing organizations. Source dates are not statements about later changes; check the current pages.

Kalshi glossary: source-checked event-contract terms