What is an ECN?

An ECN is an Electronic Communications Network that disseminates the price and size of open orders and matches buyers and sellers of securities over an electronic network.

Archipelago provides advanced and anonymous order entry and execution capabilities using a proprietary SmartBookTM software. ARCA has created a National Order Book in addition to giving customers access to all available liquidity, including other ECNs. Multiple preferences are sent with the click of a mouse.

The merger of Island and Instinet ECNs created the Inet ECN - the largest ECN in North America. INET is displayed as ISLD and INCA on the peak platforms.. Inet is an automated trading system for equity securities that gives brokers the power to electronically display customer orders. Island functions as a pure auction market -- directly matching buy and sell orders.

Brut Electronic Investment Services brings institutional investors and broker-dealers together for better information, better trades and a better market dynamic. With BRUT, you will experience fast, anonymous, and cost-efficient trading.

Bloomberg TRADEBOOK provides institutional equity traders, agency brokers and market makers innovative access to multiple sources of liquidity. Bloomberg TRADEBOOK embraces the rules and helps traders consolidate all sources of liquidity on one electronic platform. Bloomberg TRADEBOOK represents your orders in the National Quote Montage and interacts with general order flow across the NASDAQ ® system or specifically accesses liquidity from individual market makers or ECNs.

ATTAIN

The ATTAIN® ECN, "ATTN", allows its subscribers immediate and direct posting of orders to the ATTN book. Subscribers can enter orders on ATTN either at the bid, the offer, or in between the spread without market maker intervention. The best bid and offer for each security on ATTN is posted on NASDAQ. Clients can utilize the ATTN ECN to post a new "inside" buy or sell order at a price better than the best price on NASDAQ. The ATTAIN® ECN was designed to offer optimal efficiency and performance to both its subscribers and users. As an ECN, ATTAIN® instantaneously provides its subscribers with the highest level of exposure. Domestic Securities' integrity and neutrality are impeccable. All subscribers' orders are placed anonymously.