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Mark price

Mark price is the reference value a platform uses to value an open position and show its current profit or loss.

By Fredrik FilipssonFounder and editor · Two decades in advisory, hospitality and mediaEditorial review by Morten Andersen · Last reviewed 25 June 2025

Last reviewed 25 June 2025 · Educational, not advice

Information, not advice. This page is general information, not financial, investment, legal, tax, or betting advice. Prediction markets carry a real risk of loss. You must be 18+ or the legal age in your region.
In plain terms

The number used to value your position.

Mark price is the value a trading platform assigns to a contract in order to mark, or value, your open position. It is the number used to show your current unrealised profit or loss, the gain or loss you would have if the position were valued right now without closing it. Marking a position to a current value is the everyday meaning of the phrase marking to market.

The mark price is not always the same as the last traded price. The last trade can be stale or distorted by a single small order, so a venue may compute a mark from the midpoint of the best bid and offer, or from a short average, to get a fairer current value. The aim is a number that reflects where the market truly is rather than the most recent accidental print.

In leveraged or margined products on some venues, the mark price does real work beyond display. It can drive how unrealised profit and loss are calculated and, where margin is involved, whether a position is at risk of liquidation. Event contract platforms that take full payment up front have less need for this, but where margin exists the mark price becomes a number worth watching closely.

It helps to keep three prices separate. The last traded price is what changed hands most recently. The mark price is the platform reference for valuation. The settlement value is what the contract finally pays when it resolves, usually one hundred or zero on a binary event contract. A position marked at sixty today can still settle at zero.

For most users the practical point is simple. The profit or loss figure on your screen is built from the mark price, which is a snapshot reference, not a promise. It moves as the market moves, it is not money until you close or the contract settles, and the method a platform uses to set it is described in that platform own documentation, which is worth reading.

A worked example

Suppose the best bid on a contract is 58 cents and the best offer is 62 cents, while the last trade printed at 55 cents on a single small order. A platform that marks to the midpoint would set the mark price at 60 cents and value your position there, even though the last trade was 55. Your unrealised profit or loss is calculated from that 60, not from the stale print.

Illustrative only. Numbers are examples, not a quote or a prediction, and exclude fees.

A note on risk,

A mark price is a reference for valuation, not cash in hand. Unrealised profit can vanish before you close, and where margin exists an adverse mark can trigger a liquidation. Read your platform method for setting it. Stake only what you can afford to lose, never to chase a loss, and never on borrowed money. If it stops feeling like a free choice, step back. In the United States you can call or text the helpline on 1-800-GAMBLER or visit ncpgambling.org.

Common questions

Answered plainly.

What is the mark price?

It is the reference value a platform uses to value an open position and show its unrealised profit or loss. It is often built from the midpoint of the best bid and offer rather than the last traded price.

How is the mark price different from the last traded price?

The last traded price is simply the most recent trade, which can be stale or moved by one small order. The mark price is a fairer current value, often a midpoint or short average, used for valuation.

Does the mark price decide what I am paid?

No. On a binary event contract the final payout is the settlement value, usually one hundred cents for the correct side and zero for the other. The mark price only values the position while it is open.

Where do I find how mark price is calculated?

In the platform own documentation. Methods vary between venues, so check the specific rules before relying on the unrealised profit or loss figure shown on your screen.

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