As of late August this year, about eight months after their debut, the 10 new funds approved by United States regulators collectively boasted more than $52 billion, according to data from TrackInsight.

"Clearly, I wasn't being bullish enough," Hougan, CEO of crypto firm Bitwise Investments, reflected wryly. "This is going to be an area that we measure in hundreds of billions of dollars."

That remains to be seen. These products track the price of Bitcoin, which has whipsawed repeatedly since its birth 16 years ago kicked off the crypto era.

Some market players say bitcoin is inherently speculative, more akin to art or fine wine than gold and commodities, driving volatility and risk.

--Reuters--