Definition. The total supply held by entities classified as illiquid.

Technical. The liquidity of an entity is defined as the ratio of cumulative outflows to cumulative inflows over the entity's lifespan. An entity is considered illiquid, liquid, or highly liquid when its liquidity L sits at ≲ 0.25, between 0.25 and 0.75, or ≳ 0.75 respectively.

Notes. For more information, see the introductory article on Bitcoin liquidity.