How to read an implied probability
In a binary market a winning share pays $1.00, so the price reads directly as a probability. A Yes share at $0.72 is the market saying roughly 72%.
Roughly, because there are two prices. If Yes trades at $0.72 and No at $0.29, the two sides imply 72% and 71%, and the market's estimate sits in that band. Quoting a single figure to the decimal point overstates what the book says.
What sits inside the number
The pair rarely sums to exactly $1.00. The excess is the spread, which is the cost of trading against the resting orders, and it widens in thin markets. Trading fees and, on some platforms, the cost of moving capital in and out come out of the same margin.
Long shots carry a further distortion. Contracts priced under about $0.05 tend to trade above their true probability, the same favorite-longshot bias seen in other betting markets, because a cheap ticket with a large payout attracts buyers regardless of value.
Where 0xinsider uses implied probability
The live feed lists each large trade's fill price, which is the implied probability that trader paid. One fill is one side of the spread, so read it as one end of the range, not the midpoint.
