A prediction market contract that trades at 65 cents is telling you something specific: the market thinks the underlying event has about a 65% chance of happening. That one-line translation is the whole appeal of these markets. The price is the forecast, in plain probability, updating every time someone trades.
But the price alone can mislead you. A number pulled from a market nobody is trading is worth about as much as a stock quote from a company that hasn't traded a share all week. Reading a prediction market well means reading the price and the activity around it together, and knowing which of the several numbers on the screen to trust. Here's how a careful analyst does it.
The price is a probability — read it in cents
Most prediction-market contracts are binary: they pay $1 (100¢) if a specific outcome happens and $0 if it doesn't. That payoff structure is what makes the price legible. If a "Yes" contract is changing hands at 65¢, a buyer is paying 65 cents for a shot at a dollar — a position that only makes sense, on average, if the outcome is roughly 65% likely. So the price, quoted from 0 to 100, reads straight off as the market's implied probability.
This is the core skill, and it travels across platforms. Kalshi quotes contracts in U.S. cents from 0 to 100. Polymarket quotes in USDC from 0.0000 to 1.0000 — same idea, just shift the decimal: 0.65 is 65%. Either way, you're reading a probability, not a dollar value.
Two cautions before you trust the number.
Which price are you reading? The figure most sites show by default is the last price — the price of the most recent trade. In a busy market that's fine. But the last trade might be an hour old, or it might be a single small order that briefly poked above where buyers and sellers actually sit. The cleaner read is the midpoint of the bid and the ask: the best price buyers are currently offering and the best price sellers will currently accept. If buyers are bidding 63¢ and sellers asking 67¢, the market's real estimate is about 65%, even if the last recorded trade printed at 60¢. In a thin market, that gap between last price and midpoint is exactly where misreadings happen. (See bid, ask, and spread for the mechanics.)
A wide spread is a warning, not a price. When the bid and ask sit far apart — say 55¢ bid, 75¢ ask — the market is effectively shrugging. There's no consensus to read. The midpoint still gives you a number, but it's a soft one. Treat a wide spread the way you'd treat a stock with a 20-cent spread and no recent prints: the quote exists, but don't lean on it.
Read the price alongside volume, open interest, and liquidity
A price tells you what the market thinks. Three other numbers tell you how much that opinion is worth.
Trading volume is the total number of contracts traded over a period — the market's activity and attention. High volume means a lot of money and a lot of participants have weighed in, which generally makes the price more trustworthy. It's the primary signal TickerTracker uses to rank and compare markets, on the simple logic that the busiest markets are usually the best-informed.
Open interest is the number of contracts currently held open — positions entered but not yet closed or settled. Where volume is cumulative activity over time, open interest is money at stake right now. The two can diverge sharply: a market can show enormous lifetime volume but thin open interest if most positions have already been closed out. If you want to know how much real conviction is sitting behind today's price, open interest is the better gauge.
Liquidity ties it together: it's how easily you could trade without shoving the price around. A liquid market has many resting orders and a tight spread, so the price barely moves on a normal-sized trade. A thin one can lurch on a single order. Liquidity generally tracks volume and open interest, which is why high-volume markets tend to produce the steadiest, most reliable prices.
The practical move: before you quote a market's probability, glance at these three.
A 70% price backed by heavy volume, deep open interest, and a one-cent spread is a forecast you can cite. A 70% price on a market with a handful of contracts traded and a fifteen-cent spread is a guess wearing a number's clothes.
Multi-outcome markets: read the whole distribution
Plenty of the most interesting questions aren't Yes/No. "Who wins the election?" or "Who wins the tournament?" are multi-outcome markets, where each candidate or competitor is its own contract and exactly one will resolve Yes.
The useful property: in a well-formed mutually exclusive market, the implied probabilities of all the outcomes sum to roughly 100% (about $1). That lets you read the full field as a probability distribution at a glance. Polymarket builds many of these as "negative risk" markets that actively keep the outcome prices summing to about $1, so the distribution stays clean.
A worked example — illustrative numbers, not a real market:
| Outcome | Price | Implied probability |
|---|---|---|
| Candidate A | 48¢ | ~48% |
| Candidate B | 39¢ | ~39% |
| Candidate C | 11¢ | ~11% |
| Field (anyone else) | 4¢ | ~4% |
| Total | 102¢ | ~102% |
That two-cent overage isn't an error to "fix." The sum runs slightly above 100% for the same reason a sportsbook's odds do: it's the bid-ask spread and the cost of trading, spread across the field. (It can dip below 100% in a thin or stale market.) The signal you want is the shape — a clear frontrunner, a close second, a long tail — not the exact total. If you see outcomes summing to 130% or 80%, that's your cue the market is thin or the prices are stale, and you're back to the volume-and-liquidity check above.
The misreadings to avoid
Trusting a thin-market price. This is the big one, and it underlies most of the others. A precise-looking number from a market with almost no volume or open interest is not a precise forecast. The number can be precise and meaningless at the same time. Always pair the price with the activity.
Long-shot bias. Across betting and prediction markets, very unlikely outcomes tend to trade a little higher than their true odds, and heavy favorites a little lower — people overpay for lottery-ticket payoffs. A documented, decades-old pattern in this kind of market. Practically: take a contract trading at 3¢ with a grain of salt. Its "3% chance" may really be closer to 1%. The distortion is largest at the extremes and small in the middle of the range.
Mistaking volume for open interest. They answer different questions. Volume is how much trading has happened; open interest is how much is still at stake. A market that traded heavily last week but has since settled most of its positions can show big volume and thin open interest — lots of past activity, little current conviction. Citing volume when you mean open interest (or vice versa) is an easy way to overstate how live a market really is.
One more, quieter trap: a price is a probability, not a payout-adjusted dollar figure. When a platform reports a market's notional activity in dollars, that's the face value of the contracts traded — counted at $1 each regardless of the price they changed hands at, not the cash that actually moved, which is smaller. It's a measure of scale, not of the odds. Keep the two straight. The cents are the forecast; the dollars are the size.
Putting it together
Reading a prediction market is a two-step habit. First, get the probability right: read the price in cents, and in a thin market prefer the bid-ask midpoint to the last trade. Second, decide whether to trust it: check volume, open interest, and liquidity, and for multi-outcome markets confirm the field sums to roughly 100%. A price with deep activity behind it is a genuine, money-weighted forecast. A price without it is just a number.
If you're new to the format, start with what a prediction market is and how these markets stack up against polls. When you're ready to read live ones, browse the markets and practice the two-step on a busy market and a quiet one side by side. The difference will read right off the screen.