Tesla’s Elon Musk — a long-time proponent of cryptocurrencies — has sounded a note of caution for investors looking to gain from the boom in the prices of Bitcoin, Ethereum, Dogecoin and others. Elon Musk said that while he believes that crypto could be the default future currency of the earth, nonetheless, people shouldn’t invest their life savings into cryptocurrency. “First of all, I think people should not invest their life savings in cryptocurrency. To be clear, I think that’s unwise,” Tesla’s CEO warned in a video released by TMZ.