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). 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. ECNs are sometimes also referred to as alternative trading systems or alternative trading networks. History The term ECN was used by the SEC to define, "any electronic system that widely disseminates to third parties orders entered therein by an exchange market maker or OTC market maker, and permits such orders to be executed against in whole or in part". The first ECN, the Instinet, was released in 1969 and provided an early application of the advances in computing. The spread of ECNs was encouraged through changes in regulatory law set forth by the SEC, and in 1975 the SEC adopted the Securities Acts Amendments of 1975, encouraging the "linking of all markets for qualified securities through communication and data processing facilities". ECNs have complicated stock exchanges through their interaction with NASDAQ. One of the key developments in the history of ECNs was the NASDAQ over-the-counter quotation system. NASDAQ was created following a 1969 American Stock Exchange study which estimated that errors in the processing of handwritten securities orders cost brokerage firms approximately $100 million per year. The NASDAQ system automated such order processing and provided brokers with the latest competitive price quotes via a computer terminal. In March 1994, a study by two economists, William Christie and Paul Schultz, noted that NASDAQ bid–ask spreads were larger than was statistically likely, indicating "We are unable to envision any scenario in which 40 to 60 dealers who are competing for order flow would simultaneously and consistently avoid using odd-eighth quotes without an implicit agreement to post quotes only on the even price fractions. However, our data do not provide direct evidence of tacit