Prediction market glossary
Every word the board uses, defined once. Terms that name a control link straight to the live board with that control already applied, so you can read the definition and then look at the thing. Questions rather than words are on the questions page.
24-hour move
How far the leading outcome's probability shifted since yesterday, in percentage points.
Points, not percent: a market going from 20 to 25 moved five points, not 25 percent. On a typical day most markets move less than one point, so anything past five is a market that has learned something.
See also: Heating up, Implied probability
24-hour volume
What traded in the last day, rather than over the market's life.
The most direct measure of what is busy now. Sort by it and the board reorders completely from the default — a market with a huge lifetime total can be entirely quiet today.
See also: Volume, × usual volume, Heating up
Bubble size
How big a market is by whatever you have sorted on — volume by default.
Size is the sort metric and colour is the probability, so changing the sort changes what the whole picture means. Sizes are scaled to fit the screen rather than drawn to scale — the ordering is exact, the ratio between two bubbles is not.
See also: Volume, Implied probability
CFTC
The US Commodity Futures Trading Commission, the regulator Kalshi operates under.
Being CFTC-regulated is what lets Kalshi serve US residents openly, and it is also why its market list is narrower: every contract has to be approved.
Cross-venue gap
The difference between what Polymarket and Kalshi say about the same event.
Seeing both venues side by side is what this board is for. A gap is rarely free money: the two markets usually have different wording, different resolution sources or different deadlines, and the traders on each cannot always reach the other. Read both sets of rules before deciding the gap is real.
See also: Resolution source, Venue
Favourite–longshot bias
The long-observed tendency for unlikely outcomes to trade above their true odds.
Seen in racetrack betting for decades and in prediction markets since: a contract at 3 cents tends to win less than three percent of the time. Practically, it means the very cheap end of the board should be read with more suspicion than the middle.
See also: Implied probability, Prediction market
Heating up
This site's own score for markets doing something unusual right now.
It combines two signals: money arriving faster than the market's normal, and the probability actually moving. Money leads, because it is the harder of the two to fake. A market has to clear a minimum of real trading before it scores at all, which stops a market that traded five dollars against a sixteen-dollar lifetime from claiming a twenty-fold surge.
See also: × usual volume, 24-hour move, 24-hour volume
Implied probability
The price, read as a percentage. 63 cents means 63 percent.
This is the number every bubble on the board is coloured by. It is called implied because nobody voted on it: it falls out of what people were willing to pay. It also includes the cost of tying money up until the market resolves, which is why long-dated markets sit a little below what you might otherwise expect.
See also: Prediction market, Favourite–longshot bias
Kalshi
A CFTC-regulated US exchange settling in dollars.
Kalshi is a licensed exchange with ordinary brokerage accounts rather than wallets, so there is no public record of who holds what — that is why no Kalshi market carries a whale count. It publishes open interest for every market.
See also: CFTC, Open interest, Whales' favourites
Liquidity
How much money is resting in the order book, waiting to trade.
It answers a different question from volume: volume is what has already traded, liquidity is what you could trade against right now. Only Polymarket publishes it, so sorting the board by liquidity shows Polymarket markets alone — that is a gap in the data, not a verdict on Kalshi.
See also: Volume, Spread, Order book
Market maker
A trader who quotes both sides of a market to earn the spread, not because they have a view.
Worth knowing because a market maker's position looks exactly like conviction from the outside. On this board one wallet was found holding an identical three-million-dollar position on three separate candidates — that is someone taking the other side of every long shot, and it is why the whale filter counts distinct positions instead of ranking by the largest one.
See also: Whales' favourites, Spread, Order book
On-chain
Recorded on a public blockchain, where anyone can read it.
Polymarket's trades and positions are on-chain, which is why holder data exists for it and not for Kalshi. It cuts both ways: the transparency this board draws on is the same transparency that makes every position public.
See also: Polymarket, USDC, Whales' favourites
Open interest
The value of contracts currently held, rather than the value of trading.
Volume counts a contract every time it changes hands; open interest counts it once, for as long as somebody holds it. High volume with low open interest is a market being traded back and forth rather than held. Every Kalshi market publishes it and only a minority of Polymarket ones do.
Order book
The standing offers to buy and sell an outcome, at every price.
Both venues match trades through an order book rather than against a house. The price you see quoted is the best standing offer, so a large order can fill at a worse average than the headline number.
Outcome
One of the answers a market can settle on. Most have two, Yes and No.
Each outcome has its own price, and across a market they add up to about 100 percent. The board shows the leading outcome on the bubble and the full set when you open a market.
See also: Share, Resolution
Polymarket
An on-chain prediction market settling in USDC on Polygon.
Because positions sit on a public blockchain, Polymarket is the venue where you can see who holds what — which is what the whale count on this board is built from. It also publishes liquidity.
See also: On-chain, USDC, Whales' favourites, Liquidity
Prediction market
A market where you buy and sell contracts that pay out $1 if an event happens and nothing if it does not.
Because the payout is fixed at $1, the price is the market's answer to the question. A contract trading at 63 cents says the crowd, betting real money, puts the event at roughly 63 percent. Everything on the live board is one of these.
See also: Implied probability, Outcome
Resolution
The moment a market is decided and the winning contracts pay $1.
The date shown on the board is the scheduled one, and markets often resolve early when the answer arrives early. Everything hangs on the resolution source written into the market's own rules — most disputes are about wording, not about what happened.
See also: Resolution source, Outcome
Resolution source
The authority a market names in advance to decide its answer.
It is the fine print that matters most and gets read least. Two markets asking what sounds like the same question can settle differently because one names an official statistic and the other names a news agency. Always read it on the venue before trading.
See also: Resolution, Cross-venue gap
Spread
The gap between the best price to buy and the best price to sell.
A tight spread means the two sides nearly agree and you can get in and out cheaply. A wide one is the clearest sign that a market's quoted probability should be read loosely — there may be no real price in between.
See also: Order book, Liquidity
USDC
A dollar-pegged stablecoin. Polymarket prices and pays in it.
One USDC is meant to be one dollar, so a contract paying one USDC is the same arithmetic as one paying a dollar. Every figure on this board is shown in dollars regardless of which venue it came from.
See also: Polymarket, On-chain
× usual volume
How today's trading compares with what this market normally does.
A ratio against the market's own recent baseline, not against other markets — three times usual on a quiet market is as real a signal as three times usual on a busy one. Until enough days of history have been recorded the chip compares against the market's lifetime average instead, and says so.
See also: Heating up, 24-hour volume
Venue
The exchange a market lives on. This board covers Polymarket and Kalshi.
Which venue a market is on decides who may trade it, what it settles in, and which numbers exist for it at all — liquidity and holder data come from one, open interest from the other. The live board can be filtered to either.
See also: Polymarket, Kalshi
Volume
The total value of everything ever traded in a market.
The board's default sort, and the thing bubble size means. It is a lifetime figure, so it barely moves day to day — which is exactly why the board also offers ways in that measure the present instead.
See also: 24-hour volume, Bubble size, Heating up
Whales' favourites
Markets holding at least five separate positions worth $10,000 or more.
A count, not a total, and that is the whole point: four positions of a million each is one market maker and three friends, while five of $10,000 is a market people are genuinely betting on. Only counts and sums are stored — no wallet, no name, no profit figure. Polymarket only, because Kalshi publishes no holder data.
See also: Market maker, Share, Polymarket
Something here still unclear? The questions page covers the questions these words come up in, and the live board shows all of them at once.