“There’s a mass of confusion between blockchain technology, which will have a big impact, and cryptocurrencies,” Mr. McKnight said. The former “is what investors should be looking at.”
A mature business devoting large resources to blockchain projects is I.B.M. It has about 15 commercial ventures focused on supply-chain management, he said, and it has “purposely stayed away from cryptocurrencies.”
Many professional investors find promise in the core blockchain technology, even as they scoff at the notion that it can be used to reinvent money. In a note to investors this year, Joe Davis, the head of Vanguard’s Investment Strategy Group, said he was “enthusiastic about the blockchain technology that makes Bitcoin possible.” But “as for Bitcoin the currency? I see a decent probability that its price goes to zero.”
Even a believer in cryptocurrencies like Mr. Hougan said Bitcoin is inefficient, with “a slow, simple network” and limited programming capabilities.
But he wouldn’t rule it out as a portfolio holding. Because its price movements are minimally correlated with those of conventional assets, adding a modest allocation to Bitcoin to a 60 percent stock-40 percent bond portfolio could improve performance, he said. A study by Bitwise found that a 5 percent allocation would have doubled the Sharpe ratio, a measure of risk-adjusted returns, of such a portfolio between the end of 2013 and the end of March.
Because Bitcoin is so volatile, however, rebalancing the allocation is essential, Mr. Hougan added. If the desired weighting is 1 percent, he would sell back to that level whenever it reached 1.5 percent and buy more when it reached 0.5 percent.
The value of a Bitcoin rose to just under $7,000 from about $600 during the time of the study. Whether owning it or other cryptocurrencies will be as helpful if the price persistently falls remains to be seen. Mr. McKnight is skeptical.
“It’s buyer beware,” he said. “Don’t go into this space saying you’re going to pick this or that cryptocurrency without knowing anything. And you should not be using your living money.”