Business Insider executive editor Sara Silverstein discusses a recent research note from Fundstrat's Tom Lee says bitcoin could be a true substitute for gold and cannibalize some of the $7.5 trillion market. Lee estimates the cryptocurrency could be worth $20,300 by 2022. This estimate is based largely on the assumption that bitcoin can increase its share of the "alternative currency" market, which is mostly gold, from 0.7% to 5%.