Coinbase, the operator of one of the largest cryptocurrency exchanges, is considering trying its hand at bitcoin ETFs, an asset U.S. regulators have yet to approve.

“Citing unnamed sources, Business Insider’s Frank Chaparro reported today that Coinbase had contacted BlackRock for advice on how to go about creating a crypto ETF for retail investors. In July, the Financial News reported on the existence of a crypto/blockchain working group within BlackRock, the New York-based investment giant who manages the popular iShares line of ETFs,” according to Bitsonline.

Last month, nine Bitcoin-based exchange-traded fund (ETF) applications got the thumbs down from the Securities and Exchange Commission on Wednesday, preventing the digital currency from gaining more acceptance from investors who are wary of the unregulated exchanges of cryptocurrencies. The SEC’s Division of Trading and Markets rejected applications from investment firms ProShares, Direxion and GraniteShares.

Related: Turning to 2019 for a Bitcoin ETF

Other bitcoin ETF efforts have also seen multiple rejections.

The SEC stated, “Among other things, the Exchange has offered no record evidence to demonstrate that bitcoin futures markets are ‘markets of significant size.’ That failure is critical because, as explained below, the Exchange has failed to establish that other means to prevent fraudulent and manipulative acts and practices will be sufficient, and therefore surveillance-sharing with a regulated market of significant size related to bitcoin is necessary.”

Recent Efforts

Earlier this year, Coinbase launched the Coinbase Index Fund. The fund is available only to accredited investors defined as those with an annual income of $200,000 or a net worth of $1 million or more. The minimum investment is $10,000 and the fund has an annual management fee of 2%, according to Coinbase.

That fund, which is not an ETF, provides exposure to Bitcoin, Ethereum, Litecoin, Bitcoin Cash, and Ethereum Classic.

“A crypto ETF would be a retail-friendly version of the Coinbase Index Fund, which the company launched in March and is made up of Bitcoin, Ethereum, Litecoin, Bitcoin Cash, and Ethereum Classic. But its requirement that only accredited U.S. investors may participate with a minimum investment of $250,000 USD means that it has only a limited market. Which is why Coinbase, among many others, are seeking a crypto ETF that could be bought by a much larger investment pool,” according to Bitsonline.

For more information on the cryptocurrency market, visit the Bitcoin category.