The U.S. Securities and Exchange Commission (SEC) delayed making a decision on three bitcoin exchange-traded fund (ETF) proposals Monday.

The ETFs, proposed earlier this year by asset managers Bitwise Asset Management, VanEck/SolidX and Wilshire Phoenix, and filed with exchanges NYSE Arca and Cboe BZX, are all seeking to become the first such investment vehicle based on bitcoin.

The filings were published in the Federal Register in February and June, kicking off the legally-mandated 240-day clock on a final decision.

Final decisions on the Bitwise and VanEck/SolidX proposals are expected by Oct. 13 and Oct. 18, respectively.

The next decision on the Wilshire Phoenix proposal is scheduled to occur by Sept. 29.

While a number of companies have proposed bitcoin ETFs in recent years, the regulatory agency has yet to approve any, citing concerns with market manipulation, market surveillance and a potential divergence with futures trading as some issues.

Bitwise has sought to alleviate these concerns, publishing multiple reports indicating that the actual bitcoin market is smaller, more regulated and much better surveilled than expected, and that it trades tightly with CME’s futures market.

The company maintains that the bitcoin market is “extremely efficient,” once wash trading and otherwise faked volume data is excluded.

Bitwise’s ETF proposal, one of the several under active consideration by the SEC, has received support from a number of individuals in the industry, including Blockchain Capital’s Spencer Bogart; Castle Island Ventures’ Matthew Walsh; Coinbase Custody’s Sam McIngvale; the Blockchain Association’s Kristin Smith; and more than 30 others.

SEC image via Kristi Blokhin / Shutterstock