ASTRA QUANTHow to read a Yes/No market
Every Yes/No market on a prediction market page shows the same handful of numbers. Once you know what each one means, you can read any market in under a minute. Follow the steps below and check them against the live example on this page.
Updated: 1 November 2026. Educational material, not financial advice. Astra Quant is independent and not the official Polymarket site.
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Step 1. Read the exact question
The title is a summary; the precise question and the rules decide everything. “Will Bitcoin be above $X on Friday?” may refer to a specific exchange, pair and minute. “Will Team A win?” may or may not include extra time. Open the market and read the description before looking at prices.
Step 2. Check the resolution rules and deadline
Look for three things: the end date (when trading stops), the resolution source (which data or authority decides), and any edge cases (postponement, ties, cancelled events). If the rules are unclear, the price is harder to interpret.
Step 3. Read the Yes price
The Yes price is what you pay for a contract that becomes $1 if the answer is Yes. Read it as a probability: Yes at 27¢ ≈ 27% chance. If it wins, each share pays $1; if it loses, $0.
Step 4. Read the No price
The No contract pays $1 if the answer is No. Its price should be close to 100¢ minus the Yes price — here about 73¢. Buying No at 73¢ is the same view as “the chance of Yes is below 27%”.
Step 5. Look at the spread
If Yes + No adds up to more than 100¢ (for example 28¢ + 74¢ = 102¢), the extra is the spread — the gap between buying and selling prices. One cent is normal in busy markets; several cents means you lose more just by entering and exiting. The mid-point is the best estimate of the probability. More in How prediction market odds work.
Step 6. Check volume and liquidity
24-hour volume shows how much has traded recently; liquidity shows how much is available near the current price. High numbers mean the price reflects a lot of money and is harder to move. Low numbers mean the price could change sharply on a small order. Astra Quant shows both on every market card.
Step 7. Look at the chart
The price history shows how the market’s view has changed. A steady drift suggests gradual new information; a sudden jump usually means news. A flat line in a thin market may just mean nobody is trading.
Step 8. Work out the payout
Stake ÷ price = number of shares = payout if you win. At 27¢, a stake of 10 buys about 37.04 shares, paying 37.04 if Yes wins, a profit of about 27.04. The probability calculator does this instantly.
Step 9. Compare with your own estimate
The only reason to trade is a view that the price is wrong. If you think the real chance of Yes is 40% and it trades at 27¢, Yes looks underpriced to you. If you think it is 15%, No looks better. If you agree with the price, there is no edge — and watching is a perfectly good choice.
Step 10. Decide how you would exit
You can hold to resolution or sell earlier at the current price. Decide in advance what would make you sell, and remember that you can lose the full stake.
Quick checklist
- Question and rules read? Deadline and source clear?
- Yes and No prices noted; spread reasonable?
- Volume and liquidity enough for the size you want?
- Your estimate differs from the price — and you can say why?
Practise on a live market
The live example below is a current market from Astra Quant. Go through the ten steps on it, then try a practice trade with the 1000 ASCD demo tokens that come with a new account (virtual, no monetary value). Prices are based on public Polymarket data. Background reading: What is a prediction market, crypto prediction markets and sports prediction markets.
Frequently asked questions
What does the Yes price mean?
It is the cost of a contract that pays $1 if the answer is Yes. Read it as an implied probability: 27¢ means about 27%.
What does buying No mean?
Buying No means you think the chance of Yes is lower than the price implies. No pays $1 if the event does not happen.
Why do Yes and No not add up to exactly 100¢?
The difference is the spread between buy and sell prices.
What should I check before trading?
The exact question and rules, the deadline, Yes and No prices, the spread, volume and liquidity, and your own estimate of the chance.
New accounts receive 1000 ASCD demo tokens — virtual, with no monetary value.