Bill Gates, the world's third-richest person, is not a fan of bitcoin, partly for environmental reasons. According to the billionaire, not only does bitcoin use a lot of energy, it can also cause trouble for investors who may not have much money to spare, given how volatile its price is. "Elon has tons of money and he's very sophisticated, so I don't worry that his Bitcoin will sort of randomly go up or down," Gates told Bloomberg in an interview. "I do think people get bought into these manias, who may not have as much money to spare, so I'm not bullish on Bitcoin, and my general thought would be that, if you ... (full story)