Bitcoin’s transformation from putative currency to speculative asset, in other words, was effectively built into the system from the start. It’s where Bitcoin was headed all along. (Cryptocurrencies have emerged in Bitcoin’s wake that are better designed to function as currencies, but paradoxically they’re nowhere near as popular as Bitcoin.) Even though it may have been designed as a payment system and a medium of exchange, Bitcoin’s real appeal was, inevitably, going to be as what economists call a “store of value,” a kind of digital analogue to gold. Like gold, Bitcoin is valuable to the extent that people think it’s valuable: You buy it because you think someone else will pay more for it in the future. And like gold, its value can’t be inflated away by a central bank.