ODDSATLAS / THE FIELD GUIDE
How to read prediction market probabilities
Understand the percentage, check data freshness and learn why the precise rules matter more than a short headline.
1. Start with the question
Read the whole question before looking at the number. “Will a product be announced before a date?” differs from “Will it be available to everyone before that date?” A shared topic does not make two contracts comparable.
An event can contain several markets, each with its own outcomes. Identify the exact market and outcome behind the displayed estimate. A number for one condition does not answer a different question.
2. The percentage is a market estimate
For a binary contract, a price of 0.64 implies a market estimate of 64%. A bid is a buy offer, an ask is a sell offer, the midpoint is their average and the last trade is a completed transaction. Check the displayed price basis.
64% does not establish that the event will happen or mean that 64 out of 100 participants agree. It is one market signal and may be incomplete or wrong. OddsAtlas does not turn it into an independent forecast or a promised result.
3. Read the resolution conditions
Contract rules specify the result source, timing and treatment of ambiguous cases. A short title cannot replace them. Check what qualifies as “Yes” or “No” and how postponements or clarifications are handled.
OddsAtlas separates its summary and translation from the original conditions. Open the source if wording affects your interpretation. Changed rules require another translation review. Missing rules cannot be reconstructed from the title alone.
4. Check time and data quality
The fetch time records when the portal saved a source response. The observation time, when known, belongs to the quote itself. A recently fetched response can contain an older observation. Read the stated time zone; the page language does not determine it.
DEMO identifies demonstration data, STALE identifies an old snapshot and UNAVAILABLE means no usable value is available. Missing does not mean 0%. A market’s completion status and its snapshot freshness are separate properties.
5. Compare like-for-like observations
A move from 40% to 55% is an increase of 15 percentage points. Compare the same outcome, price basis and known observation times. If suitable history is missing, “no data” is the correct answer; a fabricated line is not.
Threshold questions can overlap: reaching a higher level may also satisfy a lower threshold. Do not add independent markets to make 100%. A price movement alone does not prove that a particular news story caused it.
6. Separate a deadline from a confirmed result
The event date, contract deadline and confirmation time can differ. Passing a date does not establish that a market has resolved. Until confirmation, the result may remain unknown or disputed.
A useful archive includes a confirmed outcome, its source and available history. Keeping the original URL lets you examine earlier estimates and the result of that particular condition.
7. Use the converter as a mathematical tool
Decimal odds equal 100 / p when p is a percentage. The reverse formula is p = 100 / decimal odds. For example, 40% corresponds to 2.5. There are no finite odds at 0%, while 100% corresponds to 1.
This converts between scales. It excludes fees, spreads, available offer size and execution conditions. The result does not establish a guaranteed payment or return. An informational page and trading availability are separate decisions too.