Big institutions have long sought the ability to trade large blocks of stock with minimal market reaction--anonymously. Which has made so-called "dark pools" a growth market. The likes of LiquidNet, Nyfix Millenium and others have brokerages and exchanges alike thinking about how best to pay the trend. NYSE, Nasdaq and the International Securities Exchange have all said they would pursue the niche. Nasdaq offers its Intraday Cross for free for limited time. I can understand why the exchanges would want in. They are simply meeting demand. But you have to wonder how the lack of transparency would fly with regulators. Broker-dealers will have a harder time, unless the service is run by a consortium. The information would be very valuable if controlled by one firm.

For more:
- here's an Investment Dealers' Digest article (For FierceFinance readers)