In the 1980s, human beings had been still at the center of the market, and technical systems were their aids. By 2000, the balance had shifted. The Chicago Board Options Exchange traded 104,000 classes of option. Inevitably, trading in some was quiet in 2000, despite record overall trading volumes the average class was trading only 13 contracts per day but the exchange's Autoquote system, now pervasive, continuously generates prices for all classes of options, no matter how sporadic the actual transactions in those classes, and distributes those prices to the vast array of electronic displays on the trading floor and through worldwide computer networks.

Donald MacKenzie, An Engine, Not a Camera, loc. 896