PayPal only began allowing U.S. customers to buy, sell, and hold bitcoin, ether, litecoin and bitcoin cash on Nov. 12. In 2021, it will expand that service to its whole 350 million strong international customer base, president and CEO Dan Schulman said. That will vastly expanding the number of potential mainstream retail investors.

PayPal CEO Dan Schulman's customers may already be buying BTC faster than it is mined (Photo: PayPal)