Prediction markets: the complete guide

1. What a prediction market is

A prediction market asks a question about something that has not happened yet, and lets you back the answer you think is right. When the event happens, the people who were right share the money.

It is not a casino game. No random number decides it. The real world does, and a published source named in the market before anyone bets says exactly how the result will be read.

Most of the time you are betting against the other players rather than against the house. Where the platform does hold a stake of its own, the market page says so, and that stake wins and loses on exactly the same terms as yours. That is the part most people find surprising, and it is what makes creating your own market worth doing.

2. The two kinds, and how each one pays

Every market is one of two kinds. The market page always says which, and the difference decides how you win.

Shared pot

Everyone who backs an outcome puts their stake into that outcome's pot. Once we confirm the result, the winning side splits the whole pot in proportion to what each person staked. There is no live price and no getting out early: you back an answer and you wait.

A worked example. Ten people back YES with 100 each, so the YES pot is 1,000. Six people back NO with 50 each, so the NO pot is 300. YES happens. The YES backers split the losing side's 300 between them, less the house cut, in proportion to their stakes. Each of the ten staked the same, so each takes a tenth of it, on top of their own 100 back.

The house cut is taken from the losing side only, and on this site it is currently 5.00%. A market marked "No house fee" takes nothing at all, and its page says so.

Each currency is a separate pot and settles separately, so backing an outcome in one coin never mixes with the same outcome backed in another.

Shared pot suits anything that resolves all at once: a match, an election, an award, a data release.

Order book

An order book has live prices you can trade in and out of, like a share price. You buy shares in an outcome at a price between 0.01 and 0.99, and every winning share pays exactly 1.00. A losing share pays nothing.

The price is the market's opinion of the chance. A share at 0.62 means the market thinks that outcome is about 62% likely. Buy it at 0.62 and you make 0.38 a share if you are right, and lose 0.62 a share if you are wrong.

A worked example. You buy 100 shares of YES at 0.62, which costs 62.00. If YES happens, those shares pay 100.00, so you are 38.00 up before fees. If NO happens they pay nothing and you are down your 62.00.

You do not have to wait for the result. If the price moves to 0.80 because the news went your way, you can put your shares up for sale at that price while the market is open, and the sale goes through when a buyer takes it. That is the real advantage of an order book: you can change your mind.

One thing to know before you try it: placing a sell locks 1.00 minus your price for each share until it fills or you cancel it, and it does that even on shares you already own. Selling 100 shares at 0.80 needs 20.00 free in your balance, which comes back as the sale goes through. Keep a little aside if you want to be able to take a profit.

The house fee is paid only by the order that crosses the spread and takes a price already sitting there, currently 1.50%. Posting a price and waiting for somebody to take it costs nothing, which matters when you create a market of your own. A book marked "No house fee" charges no trade fee at all, and its page says so.

Order book suits questions that creep towards their answer: will something reach a number by a date, a record, a milestone.

Two answers or many

Both kinds can be a straight yes or no, or a list of named answers such as who will win an election. In a multi-answer order book each answer has its own separate price that moves on its own.

3. Backing a market somebody else made

Open a market and you will see the question, the source that settles it, the closing time and the resolving time. Read those two times first, because they decide when your money is committed.

• Closes: the moment betting stops. Nobody can place or trade anything after it, although you can still cancel an order that never found a buyer and take its money back.
• Resolves: when we expect the result and can settle the market.

On a shared pot you choose an outcome and a stake, and that is the whole action. On an order book you choose a price and how many shares, and your order sits waiting until somebody takes the other side of it. An order nobody has taken can be cancelled and your money comes straight back.

After we enter the result we hold winnings for a while before paying them, currently 24 hours. During that window anyone who backed a player-created market can formally dispute the result, and an operator rules on it. Opening a dispute costs 5.00 USD, held from your balance: it comes back if your dispute is upheld, and we keep it if we reject it, which is what stops the window filling with complaints. We publish rulings that carry a written reason on the adjudication log.

If a question turns out to have two honest readings, we void it and return every stake. Nobody wins on ambiguity.

If a market asks whether something will happen by a date, or by the time the market is due to resolve, and that moment comes and goes with no sign of it, the answer is No and we pay the people who backed No, rather than handing everyone their stake back and calling it undecided. That covers a market asking whether a number will reach a level by then. It does not cover a market asking who wins, which one of several, or what a total came to, where nothing being announced leaves the question open and the market rules apply as they stand. Nor does it cover a market that needs a result to be declared before either answer can be true, like whether the winner of a contest is a first-time winner. That is different again from the source letting us down: if we cannot read it at all, or the figures it does give are incomplete, the market says how long we wait, and where the market says nothing we wait up to seven days from the time it was due to resolve. If it never comes good we void and return every stake, unless what the source did publish has already decided the market under its own rules, in which case we settle it.

4. Making your own market: the part everybody shares

You do not write the market yourself. You describe your idea in a sentence and the assistant writes the whole thing for you: the question, the answers, the public source that settles it, exactly how that source is read, and the two times.

The steps are the same whichever kind you build.

1. Type your idea in plain English and press Draft my market.
2. Read the draft. If it does not say what you meant, change your idea and draft it again. You cannot hand-edit the draft, and that is deliberate: every market has to be written to the same standard.
3. Choose the kind: shared pot, or order book. The order-book choice appears only on a yes/no draft.
4. Run the AI check. It is free and usually takes under a minute.
5. If it passes, pay. What you pay becomes your own opening position in your own market.
6. A real person reviews it before it goes live.

We charge nothing until the free check has passed. You do need the money sitting in your balance before you can draft at all, though, and there is a limit on how many drafts you can ask for in a day. If your market is rejected, everything you paid comes back, the minimum included. The one exception is somebody who submits low-effort proposals again and again, who may have the minimum kept.

5. Building a shared-pot market, start to finish

This is the simpler of the two and the right place to start.

A worked example

Say you type this as your idea:

Will the Bank of England cut interest rates at its September 2026 meeting?

The assistant comes back with a yes/no market, names the Bank of England's own published decision as the source, says the market settles on the rate announced at that meeting, and sets betting to stop before the announcement.

You pick Shared pot, and you choose your opening stake. The minimum is the submission fee, currently 20.00 USD, and the most you can open with is 1000.00 USD. Stake more than the minimum and your market opens with a bigger pot behind your own pick, which makes it look worth joining.

Say you stake 25. You run the free check, it passes, and you pay 25. The fee is inside that 25, never on top. Your 25 is now the opening stake on the outcome you chose, so you are the first player in your own market.

What you earn

If your market is approved and people use it, you take a share of the house cut on it. That share depends on your record as a creator: it starts at 5% on your first markets and rises to 10% once you have a record of markets that settled cleanly. It is paid after each settlement is final.

On a market that opens with no house fee there is no cut and so no share, and the market's own rules say so.

You can also seed an extra pool in one of the site tokens, so people using that token are not the first ones in. That is optional, and we charge it only if we approve your market.

6. Building an order-book market, start to finish

An order book needs somebody to put the first prices up, and for a market you create, that somebody is you. It is the fiddliest part of the process, so it is worth reading twice.

Players can create yes/no order books. Multi-answer order books are made by the operator.

You are quoting both sides, not betting both sides

You set two prices. A buy price, which is what you will pay per share to anyone who thinks the answer is less likely than you do. And a sell price, which is what you will take per share from anyone who thinks it is more likely than you do.

Your own opinion sits in the middle of the two. Somebody who thinks YES is a coin flip quotes 0.40 and 0.60. Somebody who thinks YES is about two thirds likely quotes 0.60 and 0.75. Either way, both prices are a good deal for the person quoting them. Those examples assume the current maximum gap of 0.20; a tighter limit means a narrower pair.

Nothing is a bet until another player trades against one of your quotes. You can cancel any quote nobody has taken and get it back in full.

The rules your two prices have to obey

• Each side has to lock up at least 25.00 USD worth, in whichever currency you open the book in.
• The gap between your two prices can be at most 0.20.
• The two sides together have to be worth more than the submission fee.
• Neither side can be bigger than the market's cap on how much one player may hold.

Prices are in whole cents, sizes in whole shares, and the sell price has to be above the buy price.

You back the sell side with 1.00 minus the price. Selling 100 shares at 0.75 locks 25.00, because that is what you would owe if the answer turned out to be YES.

What it costs

Suggest prices will open a book for about 52.17 USD at its cheapest view. That is the whole payment, and your 20.00 USD minimum sits inside it rather than being added on top.

What it costs depends on the view you pick, and not in a straight line. Your two sides usually need different numbers of shares to lock up the minimum, and shares are whole numbers, so the figure shifts as you drag the slider. At some settings the cheapest spot is not in the middle at all. There is no rule of thumb worth learning here: the form shows the figures it has beside the slider and on the choice card, and the button works to whatever is in the Amount box, or to the figure beside the slider when you leave it empty. Treat them as a guide rather than a promise. Neither is a floor the rules impose, so your own prices can often come to a little less.

The number to watch is the You pay line above the button. It updates as you change the four boxes. The payment screen then shows you the final figure and you agree to it there before anything leaves your balance, so nothing is ever taken that you have not seen first.

Suggest prices is there if you want the help, not something you have to use. Move the slider to your own view, type what you want to put in, and it fills all four boxes for you. You can equally ignore it and type your own four numbers, and the Amount box will then show what those boxes cost.

Let the button do it for you

You do not have to work any of that out. Above the four boxes there is a Suggest prices button with two controls: a slider asking how likely you think the first answer is, and a box for how much you want to put in.

Move the slider to your own view, type your amount, press the button, and all four boxes fill with prices centred on your number and sizes that come as close to your amount as whole shares allow. It usually lands a little under, because shares cannot be split. On the rare occasion it has to go over, a sentence under it says so.

There is also a folded explainer above the boxes, in plain English, for anyone meeting an order book for the first time.

A worked example

Will Erling Haaland score 30 or more Premier League goals in the 2026-27 season?

The assistant drafts it, puts YES at about 72%, and you pick Order book. You leave the slider where it starts, type 100 as your amount, and press Suggest prices. The boxes fill with a buy and a sell either side of your view, sized so the one payment lands on your amount where the limits allow it. On the settings in force as this was written that is a buy at 0.62 and a sell at 0.82, coming to 99.55 - your own figures are the ones the form shows you.

The trade fee on a market you create is 1.50%. You run the free check, then pay once. That single payment covers both your quotes plus a small reserve for it, with the submission fee counted inside it and never on top. The reserve comes back to your balance the moment the market opens. Your market is live with your prices on it from the first second, which is what makes it worth trading.

What you earn

On an order-book market you take a share of the fees the market collects, on the same ladder as above: starting at 5% and rising to 10% with your record, paid after settlement is final.

There is no pot cut, because there is no pot. Your own two opening quotes pay no fee either while they sit there waiting. Only the player who takes one of them pays. On a market that opens with no house fee there are no fees and so no share, and its own rules say so.

7. The closing time is the thing to get right

This is the mistake that costs creators the most money on a shared pot, and it is worth understanding before you draft anything.

It is a shared-pot rule. An order book closes at the question's own natural deadline, and the answer becoming clear while it is running is the book working as intended rather than a fault, and the price moves to meet it. A book whose answer is verifiably decided early can be settled there and then, as its own rules say.

8. What gets rejected, and why

The automated check asks six things, and a seventh whenever your idea could run as either kind. Getting them right first time costs you nothing but a minute of thought.

• Can it be settled? One named public source has to answer the exact question by the stated time, and the market has to say what happens if that source has not reported.
• Does it have one meaning? Exactly one reasonable reading, with a deadline and a timezone.
• Is it outside your control? We refuse anything you could cause or influence. "I will tweet X" and "my video hits a view count" are the classic rejections.
• Is it safe? Nothing involving harm to real people, illegal acts, or private personal details.
• Does it already exist? We refuse a market that duplicates a live one.
• Can it still be paid? The answer must not already be known when you submit, and both outcomes have to be something we can observe, settle and pay in the ordinary course of events.
• Is it the right shape? A question that creeps towards its answer, such as will something reach a number by a date, belongs in an order book, and submitting it as a shared pot is sent back with a note to try it the other way round.

Passing the check does not guarantee approval. A person may still review it, as step 6 above describes, and the platform can decline any proposal.

A good-faith attempt that misses the mark costs you nothing. The only exception is repetition: somebody who submits low-effort proposals again and again may have the minimum kept, and that is the only circumstance in which it is kept.

9. Your money, and when it moves

• Drafting is free and so is the AI check. We charge nothing until the check has passed, although you have to be holding the money before you can draft.
• On a shared pot you pay your opening stake, with the fee inside it.
• On an order book you pay your two quotes plus a fee reserve in one charge, with the submission fee inside it. The reserve returns when the market opens.
• Rejected: everything comes back on its own, the minimum included. The one exception is a creator who keeps submitting low-effort proposals, and that is the only case where we keep it.
• Withdrawn before review, or the closing time passes before anyone reviews it: everything comes back on its own, the minimum included, with nothing withheld either way.
• You can cancel a quote nobody has taken at any time and get back what it has not spent.
• A voided market returns every stake and takes no fee.
• If nobody backed the winning answer in a currency, we refund everyone who staked in that currency in full.
• If nobody took the other side at all, we refund every stake in full and take no cut.
• Placing a sell locks 1.00 minus your price per share until it fills or you cancel it, on shares you already hold as well as new ones.
• Opening a dispute costs 5.00 USD, returned if the dispute is upheld, and kept if we reject it.

Prediction markets have their own rewards category, separate from the casino, and we pay rakeback on what we kept from you rather than on what you staked. Lose a shared-pot bet and you paid the cut, so a slice of it comes back. Win one and you paid nothing, so there is nothing to return and you have the winnings instead. On an order book it is the trade fee that earns, so a trade that took a price earns whether it turned out right or wrong.

10. Where to go next

Create a market All open markets Settled results How markets pay: the full terms Adjudication log Top creators