Polymarket Information Efficiency Explained

Prices absorb reference prints and news in seconds — the same-second ETH reprice (0.815 to 0.065 within one printed second) and the 26-second multi-coin collapse are the venue's efficiency signatures. The book learns fast, and the record proves it at 250ms.

Efficiency does not mean the price is right; it means the price moves on the information — a distinction that matters for any study of venue learning rates.

Measured reprints land within one or two 250ms frames of the reference print; the tape and book shift on the same UTC second, and one-sided final-minute books (76.2%) show the market settling its information well before resolution.

The honest efficiency metric a study can compute from the archive: the frame-lag distribution between a known reference print and the book's reprint — a number the repricing and latency pages make queryable.

Fast price absorption is a claim about timing, not about correctness: the venue can be efficient and wrong (thin books, one-sided state, molding right up to a print). Studies should measure absorption speed and outcome accuracy separately — the record supports both, individually.

• Price discovery
• Repricing data
• Implied probability