The Chicago Stock Exchange, CHX, has enough faith in Microsoft Corp’s Windows NT to use it for its mission critical trading, logging and exchange management applications, in what is being billed as the first full scale NT installation on a US stock exchange. CHX, which says it will standardize around NT, is using NeTPower Inc’s Intel multi-processor-based Sparta high-availability servers and Symetra workstations running NT in the early stages of a deal expected to extend eventually to 250 workstations and 20 servers on the trading floor and for the CHX support systems. NT and Sunnyvale, California-based NeTPower was chosen after the Exchange evaluated Hewlett Packard Co and Sun Microsystems Inc Unix-based systems. It was already using HP hardware. NetPower servers have up to four Pentium Pro processors and include real-time data mirroring and system failure protection. CHX is the second largest US stock exchange in terms of the dollar value of shares traded, with $5bn shares worth of a total of $198bn traded in 1997.