A crossing network is an Alternative Trading System (ATS) that matches buy and sell orders electronically for execution without first routing the order to an exchange or other displayed market, such as an electronic communication network (ECN), which displays a public quote. Instead, the order is either anonymously placed into a black box or flagged to other participants of the crossing network. The advantage of the crossing network is the ability to execute a large block order without impacting the public quote.
Examples of crossing networks would be Liquidnet, Pipeline, ITG's Posit or Goldman Sachs' SIGMA X.