What is a crossing network?
It's an alternative trading system that matches buy and sell orders for execution without first routing the order to an exchange or other displayed market. It offers money managers the advantages of very low commissions, along with anonymity for the buying or selling account.
Where have you heard about crossing networks?
They're often spoken about in conjunction with 'dark pools', though their proponents say that the two are different. Examples of crossing networks are Liquidnet, Pipeline, ITG's Posit and Goldman Sachs's SIGMA X.
What you need to know about crossing networks.
The main purpose of a crossing network is to allow people to buy and sell outside public channels - possibly anonymously. By bypassing public channels, sales that happen over the crossing network don't affect the price of the security. Broker crossing networks don't show an order book.
In most cases, a crossing network has a set membership. When a security is put up for sale, the seller can allow any member to buy it, or he may restrict it to a certain sub-group within the crossing network.