(FORTUNE Magazine) – Every few minutes in Seoul thousands of workers guiltily exit their offices, punch a few keys on their mobile phones, and then scurry back to work. Why? Many Korean managers have told employees that if they trade stocks on office PCs, they'll be fired, explains Greg Tarr, founder of Seoul-based wireless Web consultancy M-Werks. Mobile trading may be booming in Seoul, but it's not the country's stockbrokers who are profiting--they've had to slash trading commissions to the bone to lure customers. It's Infobank, a Seoul-based wireless company that has struck paydirt with its unique wireless mobile-trading platform.

Here's how it works. When a mobile user buys or sells a stock on the Web page of a broker, the trade is confirmed in a few seconds (most South Korean mobiles still transmit data relatively slowly), all within a trading environment that has been secured against hacking by Infobank. Infobank co-CEO Junho Jang, who got his Ph.D. in computer engineering from Stanford in 1987, estimates that 40% of his revenues come from South Korean securities houses, which want their mobile-toting clients to trade stocks while driving, shopping, eating, and, yes, ostensibly working. Right now Infobank charges stockbrokers a flat monthly fee for its technology, but soon the company plans to charge brokers a fee for every trade. Considering the brush-fire growth of mobile trading in South Korea so far, that should set the cash registers ringing at Infobank. According to UBS Warburg Securities analyst Jasmine Koh, for example, South Korea already boasts the highest percentage of mobile stock trading in the world. Privately owned Infobank's sales in 2000 are forecast to hit $7 million, up from $1.3 million in 1999, though Jang won't comment on the firm's profitability.

--Neel Chowdhury