As the Securities and Exchange Commission defers signing off on bitcoin exchange-traded funds, some companies are exploring other ways to meet investors’ growing demand for cryptocurrency.

The SEC on Wednesday pushed another decision to approve Van Eck’s bitcoin ETF, extending the review and asking for feedback on the proposed rule change, according to the filing.

“The SEC has been unwilling now for several years to approve a bitcoin ETF,” said Timothy Massad, research fellow at the Kennedy School of Government at Harvard University. “So this recent action is consistent with that.”  

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SEC Chairman Gary Gensler called for more regulation for cryptocurrency exchanges in May, citing the need for greater investor protections. 

“The market has grown, but it still lacks some basic standards that we have in the security space, and that are imposed on securities exchanges,” Massad said.

Without oversight of cryptocurrency exchanges, the SEC worries investors may be vulnerable to fraud and market manipulation, he said. However, Congress hasn’t established a regulatory framework.

The SEC did not respond to CNBC’s request for comment.

While it may be a while before the SEC gives bitcoin ETFs the green light, other crypto-related funds are emerging in the meantime.

For example, Investco filed to release a pair of crypto-linked ETFs: the Invesco Galaxy Blockchain Economy ETF and the Invesco Galaxy Crypto Economy ETF.  

Rather than direct exposure to bitcoin or cryptocurrency, these ETFs invest in digital currency-related holdings, such as mining and technology companies.

Another option, the Bitwise Crypto Industry Innovators ETF, which tracks an index of crypto-adjacent companies, started in May.

“You can buy bitcoin, or you can buy some of the companies that benefit the bitcoin economy,” said certified financial planner Ivory Johnson, founder of Delancey Wealth Management in Washington.

Although these crypto-related ETFs tend to be less volatile than digital assets, there’s not as much upside potential, he said.  

“It’s not much different than if you buy a health-care ETF,” said Johnson. “Someone may buy the pharmaceutical or biotech portion, which is riskier.” 

Buyers may also turn to the Grayscale Bitcoin Trust, an investment that holds bitcoin, with limited units for sale. Daily placements are available to so-called accredited investors who meet income, net worth and experience requirements. The trust has a $50,000 minimum buy-in and 2% annual fee. 

Everyday investors may buy the asset through regular exchanges but may encounter price swings as the shares trade at a discount or a premium. 

Grayscale has said it’s committed to converting the trust into an ETF, making it available to more investors, when regulators are ready. 

“The ETF would be fantastic because you would reduce your fees, and you can redeem more shares,” Johnson said.