Arming for the data wars

FOR a “knowledge” industry in which people are supposedly the critical ingredient, the finance business uses an awful lot of machines. In cavernous trading rooms, desks buckle and groan under the weight of computer terminals. Selling these boxes has made computer firms rich. But the news and data streaming endlessly through them is a big business in its own right. Last year, the four main companies—Bloomberg, Bridge, Dow Jones and Reuters—together collected $4.4 billion of sales for providing the information that lubricates the workings of the financial markets.