How it works

What this site is for

Several venues let people trade contracts on the same real-world questions — an election, a central bank decision, whether a threshold is crossed by a date. Each publishes its own price, and none of them shows you the others. This site puts one question on one page: every venue that trades it, what each one is quoting, the recorded history of that figure, and — after the question is answered — what actually happened.

The point is comparison and context. A single price with no history and no second opinion is difficult to judge; the same price next to four other venues, a month of movement, and a record of how such figures have turned out before is something you can reason about.

A price is a probability, not a return

These contracts settle at one dollar if the thing happens and at nothing if it does not. That is the whole mechanism, and it is why the price behaves as a probability: a contract trading at 63 cents is the market saying the event happens about 63 times in a hundred. The cents and the percentage are the same statement written two ways.

This is the single most misread number on the site, so it is worth being blunt about it. A figure of 4% on a dramatic question is not a return, not a discount, and not a statement about you at all. It is the market saying the thing almost certainly will not happen — which is information about the world, and it is the reason the opposite side of that same contract costs 96 cents.

Both sides, and what each costs

Every question has exactly two sides, and both are always available. Their prices add up to the dollar the contract settles at: if one side costs 89 cents, the other costs 11. Each page and each card shows both, at the same size, because showing one is how a percentage gets mistaken for a recommendation.

What each side pays follows from what it costs. Commit a hundred dollars to a side priced at 11 cents and you hold contracts that return about nine hundred if that side is right, and nothing if it is not. The cheap side pays a lot and is seldom right; the dear side pays little and is usually right. That trade-off holds at every size, which is why the event page lets you move the amount and watch both sides reprice together.

Why the same question has several prices

Venues have different participants, different fees, and different amounts of money behind each question, so their prices for the same event rarely match exactly. The gap is usually small and occasionally not; when it is wide, that itself is worth noticing, and the event page shows the spread between the highest and lowest quote.

Volume is the other figure to read. A price backed by tens of millions of dollars traded is a considered estimate; the same price on a market with almost nothing behind it can be one transaction away from moving. Rows are ordered by volume for that reason, and pages whose liquidity is thin are labelled as such rather than presented as equivalent.

How we decide two venues are asking the same thing

This is the part that is easiest to get wrong, and getting it wrong would make every comparison on the site worthless. Two questions that read alike can settle differently — a different date, a different source, a threshold measured another way.

Where a venue publishes the cross-venue identity of a contract itself, we use it: that is authoritative and nothing needs guessing. Otherwise the pairing is scored on the wording, the entities named, the dates, and the thresholds, and anything that comes out ambiguous is resolved before the page is published rather than after. A page you can read has already cleared that check.

What settlement means

Each venue decides its own questions by its own published rules and its own named source — an official statistic, a specific data feed, a particular announcement. Those rules are reproduced on the event page, in your language, because the rule is what you are actually holding a position on. Two venues quoting the same question can settle differently if their sources differ, and venues have dispute processes that can change an outcome after trading closes.

Availability, tax treatment, and legal status differ by country and change over time. The regional availability page records what we know about which venues serve which regions, and it is data we collect rather than advice we give.

Why resolved pages stay up

When a question is answered, its page does not disappear. It keeps the full price history and gains what actually happened, which turns it into a test of the market rather than an advertisement for it.

Those settled pages are what the accuracy tracker is built from. It asks a simple question of the record: when these markets said 70%, did the thing happen about seventy times in a hundred? A price that claims to be a probability should be judged that way, and the only honest way to do it is to keep every resolved page and count.

How this site is paid for

Some of the venues listed here compensate us when a reader opens an account through our link, and some pay us nothing. Which is which is published by name on the about page.

Ranking does not depend on it. Rows sort by volume, the recommendation is computed from liquidity, fees, regional availability and how much setup a venue demands, and links to venues that pay us nothing carry no tracking. We state this here because a comparison is only worth reading if you know where its incentives sit.

Using the site

1. 1Start from the catalogue or the search box and find the question you care about. Cards show both sides priced, the venues trading it, and when it settles.
2. 2On the event page, read both sides before anything else, and move the amount to see what each side costs and what it pays at a size that means something to you.
3. 3Check the volume and the spread. A wide gap between venues, or very little money behind a price, changes how much weight the figure deserves.
4. 4Read the settlement rule and its source. This is what decides the question, and it is more specific than the headline wording.
5. 5Look at the chart. How a figure arrived where it is often says more than the figure — a price that has sat at 60% for a month is a different statement from one that reached 60% yesterday.
6. 6Compare the venues in the table: price, fee, whether you need an external wallet, and whether the venue serves your region.
7. 7If you decide to act, open the venue from the page. Everything after that happens on the venue under its own rules, and its own published figures are the ones that count.