Tiny, button-size devices that will fit almost entirely into a trader’s ears may replace the cellular phone sets that have become commonplace among floor traders at the New York Stock Exchange in the next couple of years. The earpieces, presumably from Jabra Corp, will offer the same benefits as cellular phones but with less-obtrusive equipment. The earplug supports a small bump pointing forwards that houses a microphone that can send and receive messages. The user speaks quietly into the microphone. The institution plans to spend $125m up to 1996 on cutting edge computer and communications upgrades to compete with the Nasdaq Stock Market and Reuters Holdings’ Instinet system. Within 18 to 24 months, floor traders will be issued handheld computers that offer wireless data communications. Testing of that equipment, said to rely on infra-red communication technology, should start next month.