https://www.cnbc.com/2018/05/07/bill-gates-i-would-short-bitcoin-if-i-could.html >Microsoft co-founder Bill Gates said Monday he would bet against bitcoin if he could. >"As an asset class, you're not producing anything and so you shouldn't expect it to go up. It's kind of a pure 'greater fool theory' type of investment," Gates said on CNBC's "Squawk Box."