Analyse Order Book Depth and Price History

Current price tells you the consensus probability at a moment in time. But whether that consensus is reliable depends on the market's liquidity — a deeply traded market with a tight bid/ask spread is a stronger signal than a thin market where a single large bet moved the price. And the historical price curve shows whether the probability has been stable or volatile, which matters for how much weight to put on the current reading.

Polymarket provides order book data showing the depth of bids and offers at each price level, and historical price data that reconstructs how the probability has evolved since market inception. The order book reveals whether there is genuine two-sided liquidity or whether the current price is shallow and easily moved.

Researchers evaluating the quality of prediction market signals, traders assessing entry points, and analysts building probability models use this to go beyond the headline price to an assessment of market quality.