Expiry is the moment a contract reaches the end of its life, when trading stops and the market settles to its final value based on the defined outcome.
Last reviewed 7 December 2025 · Educational, not advice
Every event contract has a fixed end. Expiry is the point at which the contract can no longer be traded and is settled against the real world outcome it was written on. Up to that moment the price moves as people trade on new information. After it, the result is determined by the resolution source named in the contract rules, and each contract settles at one dollar if its condition was met or zero if it was not. Expiry is therefore the deadline that gives the price its meaning, because it is the date the question is finally answered.
It helps to separate two dates that often sit close together. The expiry, sometimes called the close, is when trading ends. The resolution, or settlement, is when the outcome is confirmed and accounts are paid. For some markets these happen almost together, for example a contract on a figure published at a set time. For others there is a gap, because the result needs to be reported, checked, or officially announced before the market can settle. Reading the contract rules tells you exactly when each step happens and what source decides it.
Expiry matters for practical reasons beyond the calendar. As a contract nears its end, the range of remaining outcomes narrows, so the price often moves toward zero or one hundred cents and can become more sensitive to a single piece of news. Liquidity can also thin out near expiry, which means the spread can widen and a large order can move the price more than usual. None of this is a signal to act, only a reminder that the behaviour of a market late in its life can differ from the calm middle period.
Knowing the expiry also frames your own risk. A position you hold to expiry resolves at zero or one dollar with nothing in between, so the comfortable looking price in the middle is not what you keep if the outcome goes against you. You can usually close a position before expiry by trading out of it, subject to there being someone to trade with, but you are never guaranteed an exit at a price you like. Treat the expiry date as the hard boundary of the decision you are making.
Suppose a contract asks whether a named figure will be published above a threshold by the last day of a month. Trading closes at expiry on that day. If the figure is released the next morning and clears the threshold, the contract resolves yes and settles at one dollar. A holder who paid forty cents keeps the difference, while a holder of the no side loses their stake. The price along the way was only ever an estimate of this single yes or no answer.
Illustrative only. Numbers are examples, not a quote or a prediction, and exclude fees.
Holding to expiry means a position resolves at zero or one dollar, not the comfortable middle price on the screen. Prediction markets can lose you money, and a late market can move against you fast. 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.
Expiry is the point at which a contract stops trading and settles to its final value, one dollar if its defined condition was met and zero if it was not. It is the deadline that decides the outcome the price was estimating.
Not always. Expiry is when trading ends, while settlement is when the outcome is confirmed and accounts are paid. They can be almost simultaneous or separated by hours or days, depending on how quickly the result is reported and checked.
Usually yes, you can trade out of a position before it expires, but only if there is someone willing to take the other side at a price you accept. An exit is never guaranteed, and liquidity can thin as expiry nears.
As a contract approaches expiry the remaining outcomes narrow, so a single piece of news can push the price quickly toward zero or one hundred cents, and thinner late liquidity can widen the spread.
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