Why You Should Tweak Your Investments After Lofty Stock Returns

BlackRock thinks there's a case for bitcoin in a diversified portfolio — for investors who are comfortable with the "risk of potentially rapid price plunges" and who believe it will become more widely adopted, experts at the BlackRock Investment Institute wrote in early December.

(BlackRock offers a bitcoin ETF, the iShares Bitcoin Trust, IBIT.)

A 1% to 2% allocation to bitcoin is a "reasonable range," BlackRock experts wrote.

Going beyond that would "sharply increase" bitcoin's share of a portfolio's total risk, they said.

For example, a 2% bitcoin allocation accounts for roughly 5% of the risk of a traditional 60/40 portfolio, BlackRock estimated. But a 4% allocation swells that figure to 14% of total portfolio risk, it said.