What Are Prediction Markets and How Do They Work?
Prediction markets are markets where participants buy and sell contracts tied to the outcomes of future events. These events can involve elections, economic indicators, sports, business developments, public policy, and other questions whose outcomes can eventually be evaluated.
The prices of these contracts can provide a snapshot of what market participants collectively expect to happen. Because prices change as participants trade and respond to new information, prediction markets can offer a way to track changing expectations over time.
However, a market price is not a guarantee or a definitive measure of an event’s true probability. Understanding how prediction markets work requires looking at contract prices, trading activity, settlement rules, and the limitations of market-based forecasts.
What Is a Prediction Market?
A prediction market is a marketplace where contracts are linked to the outcome of a future event or a question with a defined resolution.
For example, a market might ask whether a central bank will lower interest rates by a specified date. Participants trade contracts associated with the possible outcomes, and the prices of those contracts change as buying, selling, and expectations change.
Other prediction markets may focus on questions such as:
- Whether a candidate will win an election
- Whether an economic indicator will exceed a specified threshold
- Whether a company will announce a particular development
- Whether a policy proposal will be approved by a certain date
- Whether a sporting event will have a particular outcome
The questions, available contracts, and settlement conditions vary by platform. A market is only meaningful when its question and resolution criteria are sufficiently clear to determine the outcome.
How Do Prediction Markets Work?
Although platforms use different trading systems, many prediction markets follow a similar process.
1. A specific question is defined
The market begins with a question about a future event. The question should have a defined resolution method and a clear deadline or settlement condition.
For example, a market might ask whether a specified economic indicator will exceed a particular value in a named reporting period.
The exact wording matters. Different reporting dates, data sources, or definitions can produce different outcomes even when two markets appear to ask the same question.
2. Contracts represent possible outcomes
In a binary prediction market, contracts commonly represent two possible outcomes, such as Yes and No.
Under a common structure, a winning contract pays a fixed amount, often $1, while a losing contract pays nothing. Other contract types and payout structures also exist, so the market’s terms must always be checked.
3. Participants trade at available prices
Participants can buy or sell contracts at prices offered in the market. Their orders, along with the trading activity of other participants, influence the prices that are available.
A contract’s price may change when new information emerges, when participants reassess an event, or when changes in supply and demand affect trading.
4. The event is resolved
Once the relevant event occurs or the market’s resolution conditions are met, the platform determines the outcome according to its published rules.
The resulting settlement determines which contracts receive a payout, if applicable. Disputes, delayed information, ambiguous wording, and platform-specific procedures can affect resolution timelines.
How Do Prediction Market Prices Represent Probability?
One reason prediction markets attract attention is that their prices can be interpreted as implied probabilities.
In a simple binary market where a winning contract pays $1 and a losing contract pays $0, a Yes contract priced at $0.60 has a gross payout-based break-even probability of 60%, before fees and other costs.
This is the basic intuition behind interpreting a price as a probability: a participant paying $0.60 for a contract that pays $1 if the event occurs is paying 60 cents for a potential dollar payout.
However, this does not mean the event has an objectively verified 60% chance of occurring.
The price is shaped by market participation, available information, trading constraints, liquidity, and the incentives of participants. Fees and differences between buying and selling prices can also affect the economics of a trade.
For a more detailed explanation, see our Guides & Research coverage as we expand our analysis of market prices and probability.
Why Do Prediction Market Prices Change?
Prediction market prices can move as participants respond to new information or reassess existing evidence.
Common influences include:
- New information: Polls, official announcements, economic releases, court decisions, and other developments can change expectations.
- Changing interpretations: Participants may interpret the same information differently or revise earlier assumptions.
- Trading activity: Concentrated buying or selling can move prices, particularly in markets with limited liquidity.
- Market participation: Changes in the number and composition of participants can affect available prices.
- Time remaining: As a resolution date approaches, uncertainty may decline, although unexpected developments can still cause substantial changes.
A price movement does not necessarily reveal why a market moved. Without additional evidence, it is difficult to distinguish a response to meaningful information from a change driven primarily by trading activity or limited liquidity.
What Is the Difference Between Prediction Markets and Polls?
Polls and prediction markets can both provide information about expectations, but they measure different things.
A poll collects responses from a sample of people about their opinions, preferences, or stated intentions. Its results depend on factors such as sampling, question wording, response rates, and the methods used to estimate the wider population.
A prediction market records prices and trading activity associated with defined outcomes. Its prices reflect the interaction of participants’ expectations, available capital, market rules, and willingness to trade at particular prices.
These sources can complement one another, but neither should automatically be treated as definitive. A poll can be affected by sampling and measurement error, while a prediction market can be affected by limited liquidity, participant composition, and trading constraints.
When the two disagree, the difference is a reason to investigate the underlying assumptions and evidence, not to assume that one source must be correct.
What Are the Limitations of Prediction Markets?
Prediction markets can be informative, but they have important limitations.
Market prices are not guarantees. An event can occur even when its implied probability is low, and an event assigned a high implied probability can still fail to happen.
Liquidity varies. A price in a thinly traded market may be more sensitive to individual orders than a price in a market with substantial trading activity.
Market rules matter. Ambiguous questions, unusual settlement conditions, or differences between platforms can make comparisons misleading.
Participants may have incomplete information. Market prices reflect the information and judgments incorporated into trading, not necessarily all relevant evidence.
Fees and trading constraints affect results. The displayed price may not be the price at which every participant can transact, and transaction costs can change the economics of a position.
These limitations mean that prediction market prices are best treated as evidence to evaluate alongside other sources, rather than as stand-alone proof of what will happen.
Are Prediction Markets the Same as Sportsbooks?
No. Prediction markets and sportsbooks can both display prices associated with uncertain outcomes, but their contract structures and operating models can differ.
A sportsbook typically offers odds on specified sporting outcomes and accepts wagers under its own pricing and settlement rules. A prediction market may allow participants to trade contracts with other participants, with prices changing through market activity.
The distinction is not identical across every platform. Some products may share features, and the legal treatment of particular services varies by jurisdiction and product structure.
When comparing the two, it is important to examine how prices are formed, what a contract pays, what fees apply, and how the outcome is settled.
The Bottom Line
Prediction markets allow participants to trade contracts tied to future events. Their prices can provide a useful view of market expectations, and in some common binary-contract structures, those prices can be translated into payout-based implied probabilities.
But prices are not the same as certainty, and they do not independently establish an event’s true probability. Liquidity, market rules, participant behavior, and new information all affect what a price means.
Understanding those mechanics is the starting point for evaluating prediction markets carefully. As we expand our Prediction Markets coverage, we’ll examine how prices change, how forecasts can be evaluated, and what market signals can and cannot tell us.