Amarantus Bioscience Holdings Inc (AMBS)

[brickbybrick]

An automated system that matches buy and sell orders for securities. An ECN connects major brokerages and individual traders so that they can trade directly between themselves without going through a middleman. The ECN makes money by charging a fee for each transaction. ECNs make it possible for investors in different geographic locations to quickly and easily trade with each other. The Securities and Exchange Commission requires ECNs to register as broker-dealers.

http://www.investopedia.com/terms/e/ecn.asp

More here;
https://www.sec.gov/news/studies/ecnafter.htm