Dogecoin jumps 20% as Musk says he's working to improve its efficiency

Dogecoin, a meme-based cryptocurrency, surged by more than 20% to over 50 cents on Friday after Tesla CEO Elon Musk said he was working with developers to improve its "system transaction efficiency". Musk added on Twitter that it was "potentially promising". With a market value of over $70 billion, Dogecoin is the fourth-largest cryptocurrency, according to CoinMarketCap.