Scarcity drives value, according to PlanB in his regression analysis of Bitcoin's ($BTC) stock-to-flow (SF) relationship. SF is the current production against the current supply, a measurement of scarcity. Bitcoin is the first digitally scarce object ever and is quickly approaching a stock-to-flow ratio of gold (Gold at 62 SF, Bitcoin at 25 SF). As halvings occur, Bitcoin's SF should overtake gold by 2022. Bitcoin's SF ratio and market value have a statistically significant relationship too and can be used with relative confidence to predict future prices, according to PlanB.