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What is ECN?

An electronic communication network (ECN) is a type of computerized forum or network that facilitates the trading of financial products outside traditional stock exchanges. An ECN is generally an electronic system that widely disseminates orders entered by market makers to third parties and permits the orders to be executed against in whole or in part. The primary products that are traded on ECNs are stocks and currencies. ECNs are generally passive computer-driven networks that internally match limit orders and charge a very small per share transaction fee (often a fraction of a cent per share).^[1]

The first ECN, Instinet, was created in 1969. ECNs increase competition among trading firms by lowering transaction costs, giving clients full access to their order books, and offering order matching outside traditional exchange hours.^{[citation needed]} ECNs are sometimes also referred to as alternative trading systems or alternative trading networks

Function:

ECNs are used as stock exchanges for off-the-floor trading.^[8] To trade with an ECN, one must be a subscriber or have an account with a broker that provides direct access trading. ECN subscribers can enter orders into the ECN via a custom computer terminal or network protocols. The ECN will then match contra-side orders (i.e. a sell-order is “contra-side” to a buy-order with the same price and share count) for execution. The ECN will post unmatched orders on the system for other subscribers to view.^{[citation needed]} With ECN, buyers and sellers are able to trade anonymously,^[9][10] with the trade execution reports listing the ECN as the party.

ECNs allow its customers to trade outside traditional trading hours.^[11] Some ECN brokers may offer additional features to subscribers such as negotiation, reserve size, and pegging, and may have access to the entire ECN book (as opposed to the “top of the book”) that real-time market data regarding depth of trading interest.^{[citation needed]} ECNs are also considered to be effective for handling small orders.^[10]

ECNs are generally facilitated by electronic negotiation, a type of communication between agents that allows cooperative and competitive sharing of information to determine a proper price.