Gary Gensler, chair of the U.S. Securities and Exchange Commission, said Wednesday that cryptocurrencies like Bitcoin (BTC-USD) represent a "speculative asset class" that requires more regulation to meet its potential. Gensler told CNBC that he was "pro-innovation" but wanted "rules of the road" for crypto to provide adequate investor protection, maintain financial security and fight illicit activity, like fraud and ransomware. "If it's going to meet its potential, it needs to come within public policy frameworks," he said of the cryptocurrency market. The SEC chair said "it's alright" if people want to speculate in cryptocurrency, but he wanted to close gaps in regulatory authority -- a move he thinks will be "good for investors" and "good for technology." Gensler said that most tokens fall under the category of "securities," and therefore already come under the SEC's authority. However, the top securities regulator argued that the framework gets more complicated for other