Is a Prediction Market Price the Same as Probability? Not Exactly

Price can approximate probability, but do not overread it

If a Yes contract trades at 0.60, people often say the market implies a 60% probability. That is useful shorthand, but not the full truth. The price may reflect market beliefs, but it is not an oracle or a pure probability.

The CFTC’s prediction markets page explains that event contracts sit inside specific rules and regulatory contexts. Product docs such as Polymarket Docs also make clear that market rules, settlement, and trading mechanics matter.

Why price can differ from probability

When prices are more useful

Prices are more informative when the market has meaningful depth, clear rules, and objective settlement sources. If the market is tiny, wording is ambiguous, or resolution may be disputed, the price is a mixture of belief, emotion, and liquidity pressure.

Check Yourself

Why is a 0.60 Yes price not exactly the same as a true 60% probability?

Suggested answer: Because market prices also reflect liquidity, fees, trader composition, settlement rules, and information asymmetry.

Further reading: CFTC Prediction Markets · Polymarket Docs · Prediction Market

17:59

下一篇

18:00

Topic

Prediction Markets（预测市场）

Article 8

URL Slug

resolution-criteria-before-trading-event-contracts

中文标题

买预测市场前，为什么一定要先读结算规则？

中文摘要

预测市场交易的不是你脑中的事件，而是合约里写明的结算条件。规则读错，方向对也可能亏钱。

中文正文

你交易的是合约文字，不是新闻标题

很多人在预测市场亏钱，不是因为判断事件方向完全错，而是因为没有读清楚结算规则。新闻标题说“某人赢了”，但合约可能要求“官方认证”“某日期前宣布”“特定数据源确认”。现实事件和合约事件不是永远相同。

这也是为什么预测市场文章不能只讲“概率”。真正要先读的是：事件定义、结算来源、截止时间、争议处理和例外情况。CFTC 的 prediction markets 页面和 Polymarket 的 文档都能提醒你，事件合约有自己的规则框架。

读规则时看这 6 件事

一个实用习惯

下单前写一句话：“我买的是这个合约会按 X 来源在 Y 时间前结算为 Yes，而不是我觉得新闻方向偏 Yes。”这句话如果写不出来，就说明你还没有真正理解合约。

答题

为什么预测市场里“方向判断对”仍然可能亏钱？

参考答案：因为合约可能按特定规则、时间和来源结算；现实事件和合约结算口径可能不同。

延伸阅读：CFTC Prediction Markets · Polymarket Docs · Investopedia Event Contract

English title

Why You Must Read Resolution Criteria Before Trading Event Contracts

English summary

Prediction markets trade contract-defined outcomes, not the event in your head. If you misread the rules, you can be right and still lose.

English body

You trade contract text, not headlines

Many prediction-market losses come from misreading resolution rules, not from being completely wrong about the event. A headline may say someone won, while the contract may require official certification, announcement before a specific date, or confirmation by a named source. The real-world event and the contract event are not always identical.

That is why probability is not the first thing to read. Start with event definition, settlement source, deadline, dispute handling, and exceptions. The CFTC’s prediction markets page and Polymarket Docs both point users toward the rule-based nature of event markets.

Six things to check

Practical habit

Before trading, write one sentence: “I am buying this contract because it will resolve Yes by source X before time Y, not because the news feels bullish.” If you cannot write that sentence, you have not understood the contract.

Check Yourself

Why can you be directionally right and still lose in a prediction market?

Suggested answer: Because settlement depends on specific contract rules, timing, and sources; the real-world event may not match the contract’s resolution criteria.

Further reading: CFTC Prediction Markets · Polymarket Docs · Event Contracts