In its relatively short existence, bitcoin has proved extraordinarily volatile, sometimes gaining or losing more than 40% in price in a month or two. Any asset subject to such sharp swings may be catnip for traders but of limited value either as a reliable medium of exchange (to replace cash) or as a risk-reducing or inflation-hedging asset in a diversified portfolio (to replace bonds).
Assessing the merits of bitcoin as an investment can be problematic. Adding it to a
portfolio could mean paring back the allocation to investments such as stocks, property, or fxed income. The owner of stocks or real estate generally expects to receive future income from dividends or rent, even though the size and timing of the payoff may be uncertain. A bondholder generally expects to receive interest payments as well as the return of principal. In contrast, holding bitcoin is similar to holding gold as an investment. Even if bitcoin or gold are held for decades, the owner may never receive more bitcoin or gold, and unlike stocks and bonds, it is not clear that bitcoin offers
investors positive expected returns.