Glossary
Liquidity
How much you can trade without moving the price much. On Polymarket that is resting size near the touch — not yesterday’s volume headline.
Liquidity is how much you can trade without moving the price much. On Polymarket that is resting size near the touch, plus makers who will replace it — not yesterday’s volume headline. A weather city contract can print millions over a month and still be a 3¢-wide, $1k-deep book at 2am.
Two useful checks: spread (what you pay to go and back) and depth (how many dollars sit within a few cents of mid on the order book). Volume without depth is a tape of small prints; depth without volume is a quote that may be spoofed or stale. You want both. Liquidity is local to the token: YES can be tradeable while NO is empty. NegRisk clusters can look liquid on the favorite and dead on the 40th seed.
Category hubs on Polydata rank open markets by volume so you can find where the tape actually is — they are not a guarantee of a clean fill. The whale feed is the stress test: if a $50k take moves a name 12 points, that book was not liquid for that size, whatever 24h volume said. Open interest tells you how much inventory is stuck; it does not by itself make the next fill cheap.