3. Stage: Medium of exchange
When money is fully established as a store of value, its purchasing power will stabilize. Having stabilized in purchasing power, the opportunity cost of using money to complete trades will diminish to a level where it is suitable for use as a medium of exchange. In the earliest days of Bitcoin, many people did not appreciate the huge opportunity cost of using bitcoins as a medium of exchange, rather than as an incipient store of value. The famous story of a man trading 10,000 bitcoins (worth approximately $94 million at the time of this article’s writing) for two pizzas illustrates this confusion.