American carmaker Tesla said on Monday that it had invested around $1.5 billion in bitcoin, an internet-based form of money. The company is expected to begin accepting the digital currency as payment for its cars and other products in the near future. The announcement from one of the best-known American car companies sent the price of bitcoin up more than 10 percent. Tesla chief Elon Musk is a supporter of the digital currency. In recent weeks, Musk used the social media website Twitter to praise bitcoin. Musk said a week ago that bitcoin was “on the verge” of being more widely accepted by investors. Last December, he asked if it was possible to do large business deals in the currency.