Bitcoin dips from ~$40.7K to $39.7K after Senator Elizabeth Warren says that regulation of cryptocurrency should start sooner rather than later, before small investors are wiped out.The question is not just regulation, she said in an interview on CNBC. "The question is how it's aimed. Who takes advantage when there's no regulation? It's the big guys."The aim isn't to restrict choices in investing, Warren said. Rather, those who profit from the lack of regulation are the shady characters and the "big guys", she said."I want people to have the freedom to invest... I just don't want a system where the big guys, where the shadowy guys, where the guys you never quite see, can get out there and do pump and dump, can defraud people, can take in a lot of folks' money and then disappear."Warren thinks digital currency is "very interesting." Digital currency and central bank digital currency "may