Bitcoin's reliability remains suspect despite its growing legitimacy as an investing option, a currency expert said Tuesday.
The New York Stock Exchange launched a bitcoin index on Tuesday. It marks the first exchange-calculated index for the currency, with a real-time price tied to the Coinbase marketplace.
Despite bitcoin's increasing use as an asset—including an exchange-traded fund launched earlier this year—its reliability makes it tough to classify as a real currency, said Win Thin, senior vice president and global head of emerging markets at Brown Brothers Harriman.
"It's hardly a reliable store of value," said Thin in a CNBC "Closing Bell" interview, referencing bitcoin's price fluctuations.
Bitcoin is currently trading at about $232. As recently as November 2013, it was worth nearly $1,000, and that volatility strikes down some of its benefits as a currency, Thin contended.
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However, he noted that it remains a viable method of transaction.
Matt Roszak, founding partner at Tally Capital, said the launch of the index is a "stepping stone" for bitcoin's adoption by global institutions.
"The NYSE's adoption of this tracker is a major milestone for bitcoin," he said on "Closing Bell."
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Roszak added that the currency has received a bad reputation, hurting perceptions of its value.