Investing.com - Bitcoin has bottomed now that the tax-selling season is behind the market, but its rebound may be limited until institutional investors join the buying, according to one veteran trader."All the sellers had sold, there wasn't any lower for it to go," says Bill Baruch, president and founder of Blue Line Futures, a leading commodities and futures brokerage firm in Chicago. "People were ready to buy when tax season ended. It was herd sentiment."Baruch says that sentiment was enough to take bitcoin from its bottom of around $6,000 up to $9,500 because traditional players had returned to the market and were willing to speculate again. But that may be it for now."I think the $10,000 level is going to be tough to crack," he warns. "It's a psychological level."The next big hurdle is what he calls the "regulatory overhang." Regulators around the word appear intent on cracking down, but have yet to take much action, so the shape of regulation is still an unknown. "That's what everyone wants to know," says Baruch. "I think it's holding back institutional investors."