A source of market liquidity that is created through dark pools (dark liquidity pools) or black pools (black liquidity pools). More specifically, it constitutes the trading volume that is not revealed to the market (and hence not visible to the public), though it is up for execution. This source of liquidity consists of the dark pool sector under the guise of hidden orders and reserve orders either on the books of floor brokers and specialists or within dedicated venues such as crossing networks, proprietary desks, and ECNs.

It is also known a hidden liquidity or dark pool liquidity or black pool liquidity.