Automated market maker

Three mechanisms put a number on the screen in this sector, and this is the one that cannot fail to produce one. That property is worth understanding before you read any price on Futuur, Manifold, or an AMM market on Myriad or Limitless, because it is the difference between a market telling you something and a market telling you nothing in exactly the same typeface.

How it works

Replace the queue of human orders with a funded pricing function. You always get a quote, because the function always has one. The quote moves against you as your order grows, because the function has to stay solvent against the position it is taking. Myriad's AMM documentation states the constraint that makes the output readable at all — outcome prices always sum to $1.00, so a displayed $0.60 is the curve's implied 60%. Futuur's own help centre describes the behaviour plainly on the other side of the trade, saying the automated market maker determines the price where the order book is empty and charges a higher price the more you trade, to limit its risk exposure.

Three things follow, and none of them is true of a book.

1. Slippage is your own footprint, and it is not in any fee schedule. On a book a large order eats successive levels that were put there by other people. On a curve a large order moves the curve, and the average price you pay is strictly worse than the price you were shown. No venue publishes this as a rate, because it depends on your order against that specific market's depth. On a thin market it is routinely larger than the fee.
2. Somebody funded it, and they are holding the other side. Liquidity providers supply the depth and collect a share of the fee. They are not taking a view on the question. On Manifold the creator seeds the pool with the creation fee, which is why a market with one participant still quotes.
3. Low volume and a confident price coexist. This is the single most misleading combination in the sector, and it has nothing to do with the venue being careless. A formula has no way to express "nobody has been here."

Most AMM venues are hybrids, and the card says so

The enum value records where the price comes from when nothing else can supply one, not that there is only one mechanism. Manifold's own FAQ says it uses a combination of limit orders and an automated market maker, and that trades fill against limit orders first and the AMM second. Futuur takes ordinary market and limit orders and falls back to the curve. Limitless and Myriad do neither — each runs AMM markets and order-book markets as distinct market types, with their own fee schedules, so which one you are in is a property of the market rather than of the moment. Both cards carry clob, because the book is where most of their open markets sit. Of the five cards here carrying economics.liquidity_model: amm, four also carry capabilities.order_book: true.

It is not a parimutuel pool, even though both always show a number

A parimutuel pool shows you an implied price that is provisional until the pool closes, and there is nothing to sell before then. A curve shows you a price you can take now and close out of later, at whatever the curve says then. The two look similar on a screen and behave nothing alike the moment you want out.

Why it matters here

You will read a two-decimal number as a forecast. On 19 September 2026 Myriad's public API returned 70 open AMM markets by default, and of the 39 denominated in a stablecoin the median had traded about $11,500 and carried about $1,000 of liquidity. Each showed a confident probability. The number was the curve's arithmetic, not a crowd's opinion. Where the liquidity comes from has the four measurements that tell the two apart.

You will compare the fee against a coefficient venue and get the ranking backwards. An AMM here charges a percentage of what the fill costs. A contract bought at 50 cents with a 2% AMM fee — what 17 of Myriad's AMM markets charged on 4 October 2026 — carries one cent of charge, which is 1% of the dollar it pays, not 2%. Every card in this catalogue normalises to the effective fee at fifty cents for exactly this reason; what a trade actually costs does the conversion for all four bases in use.

You will size an order off the displayed price. The quote you see is the price of an infinitesimal trade. What you pay is the average along the curve, and on a market holding a thousand dollars of liquidity a few hundred dollars of order is a large fraction of it. Place a small order first and read what came back.

You will assume the depth is somebody's conviction. It is not. It is an inventory position someone took to earn fees, and it will quote you just as confidently into a question whose resolution source has already said something the market has not noticed.