Bitcoin jolted by regulation worries, falls 7 percent on extended selloff TOKYO/SINGAPORE (Reuters) – Bitcoin extended its sharp tumble of the past 24 hours, skidding more than seven percent on Wednesday in a rapid downturn in fortunes as investors were spooked by fears regulators might clamp down on an asset whose value has skyrocketed in the past year. The price of the world’s biggest and best-known cryptocurrency fell to as low as $10,567 on the Luxembourg-based Bitstamp exchange, not far…