预测市场的经济学解释

The Economics of Prediction Markets Explained How prediction markets turn information into prices through incentives, liquidity, resolution, payouts, and market design.

Quicknode September 29, 2026 — 15 min read

The 2024 US presidential election had billions watching. Most waited for a name to see whether their candidate had won.

Others watched something else: the price of who would win and how much they could make if they were right.

Welcome to prediction markets: the "put your money where your mouth is" thesis in action.

Election markets saw billions of dollars flow in from traders expressing their beliefs with a price: a candidate trading at 60 cents implied a ~60% chance of winning.

But where did that 60% come from?

It came from people trading against one another, each with different information, incentives, capital, and risk appetite.

Today, let's explore the economic engine behind these prediction markets.

How Do Prediction Markets Turn Information Into Prices?

Prediction markets start with disagreement and end with one winner.

Participants hold different information, think about the same event differently, or simply assign different odds. The market gives those differences a price.

Beliefs Become Trades and Trades Become a Price

Now, let's play out an election prediction market that pays $1 if a candidate wins and $0 if the candidate loses.

The contract currently trades at $0.60. That means the market requires $0.60 to buy a claim that pays $1 if the candidate wins and $0 if they lose.

Trader Belief in winning How $0.60 looks Move A 70% Cheap Buys YES B 50% Overpriced Buys NO at $0.40

As more participants buy and sell, their orders compete.

Buyers push prices higher when they see value.

Sellers push them lower when they do not.

New information, like a poll or a debate stumble, changes those calculations, so prices move with it.

The resulting price is the price at which the market can currently match buyers and sellers. We call it the marginal price of disagreement.

When Does That Prediction Market Price Actually Represent Probability?

In a perfect world, a $0.60 price can be read as: the candidate has a 60% chance of winning.

That holds when the only thing traders care about is their belief in one outcome of an event.

But in the real world, several forces can bend traders' beliefs, and with them the price, away from the true underlying probability.

What bends the price How it shows up Effect Low liquidity One order can move the market several cents Price movement can be manipulated with volume Fees & trading costs Kalshi's fee peaks at 1.75¢ per contract at a 50¢ price A trader who believes 51% won't buy at 50¢, so small edges never reach the price Time

Price is observable, but probability needs to be inferred. How good that inference becomes depends partly on the people putting capital behind it.

So who is playing the game?

Who Participates in Pricing a Prediction Market?

Every price is the culmination of different players' beliefs, reasons, and goals. More importantly, their incentives differ too.

Participant Why they trade What they contribute Informed traders Profit from information or analysis they believe the market has missed Move prices toward truer odds Speculators Take a view on whether the current price is wrong Add trading activity and competing beliefs Hedgers

Did you know? Arbitrageurs took about $40 million out of Polymarket between April 2024 and April 2025.

These participants don't need the same beliefs, or even the same reason for trading, for the market to work.

If it's so random, what makes information worth putting money behind in the first place?

Incentives: Why Do People Trade Predictions?

Every participant in the market expects some return. Is it all about dollars? There are several reasons information becomes a tradable position.

Monetary Incentives to Reveal Information Through Prediction Markets

The most direct incentive is profit. It's simple math: belief minus price minus fees.

But trading profit is only one part of the incentive system. As we saw, there are different participants, and the market pays each of them different incentives.

Incentive Who earns it What it encourages Trading profit Informed traders, speculators Finding and trading on mispriced information Arbitrage profit Arbitrageurs Correcting inconsistent prices across contracts or markets Spread / maker rebates