(Bloomberg Businessweek) -- Here are some things with a total market value in the neighborhood of $40 billion: Insurance giant Prudential Financial Inc., the manufacturer Carrier Global Corp., and, at just a few billion less, Southwest Airlines Co. Or, for a recent price of about 30¢ each, the supply of Dogecoin, the cryptocurrency that started as a joke in 2013. After climbing more than 6,000% this year in a hockey-stick rally, it’...