What is Bitcoin perp basis?
Basis is the difference between a derivative price and spot. For perpetuals it tends to hover near spot because funding pulls it back, so a widening basis signals strong directional demand and a negative basis signals the perpetual trading below spot.
How it is calculated
The page follows the perpetual-minus-spot relationship as a series, using the same index reference that anchors funding. It is closely related to funding: a rich basis and positive funding usually describe the same crowded-long condition.
How to read it
A positive, widening basis means perpetuals trade above spot and leverage is leaning long. A basis that flips negative shows perpetuals trading below spot, a defensive or short-leaning condition. Basis extremes tend to coincide with positioning stress rather than calm markets.
What it does not tell you
Basis reflects leverage demand, not fair value or direction, and it overlaps heavily with funding. Live values and the full term structure are available in the authenticated app.