Dogecoin, the cryptocurrency that started out as a joke in 2013, now has a market cap of $40B after growing nearly 400% in the past seven days (Ryan Browne/CNBC)

Dogecoin, the cryptocurrency that started off as a joke in 2013, now has a market cap of $40B after rising practically 400% previously seven days — – Dogecoin is a cryptocurrency based mostly on the “Doge” meme, which rose to recognition in late 2013. It began out as a