I keep thinking the environmentalists are going to campaign against the crypto-currencies, and the huge amounts of electricity and computing power consumed when mining. I read recently where a new bitcoin was now taking 20 barrels of oil to produce.
Doesn't seem very green.
https://www.buybitcoinworldwide.com/...profitability/
And while any single cryptocurrency is limited in scope by algorithms and block chains (bitcoin caps at 21 million), that doesn't protect you from another cryptocurrency's IPO and becoming popular.
Strikes me as the 21st century's version of tulip bulbs.