Zhou Shuoji is not a bitcoin believer. He says the cryptocurrency will never replace its traditional forebears, and he calls most of its proponents fanatics. But for Zhou, a 35-year-old high-speed trader in Beijing, bitcoin is also too good to resist. His computers trade it 24 hours a day, seven days a week. Using lightning quick orders, they profit from tiny price discrepancies on the myriad venues where it changes hands. #@nik #pub