The U.S. Securities and Exchange Commission (SEC) extended its review of the Ark 21Shares bitcoin exchange-traded fund (ETF) application, as it continues to look at applications from traditional finance heavyweights like BlackRock and Fidelity.

Ark Investment Management and 21Shares, which have been seeking an ETF approval since 2021, filed for the first potential bitcoin ETF application again earlier this year after a second effort was rebuffed by the SEC. The SEC has traditionally rejected spot bitcoin ETF products on grounds of potential market manipulation and inadequate consumer protections against harmful activity.

If an ETF is approved, it would give a broader swath of the general investing public access to trading and holding bitcoin’s value without having to hold the digital asset itself.

Cathie Wood, Ark Invest’s CEO, told Bloomberg on Monday that she expected a delay in a decision on her firm’s application, but that the SEC will ultimately approve several applications simultaneously.

“Because most of these essentially will be the same, it will come down to marketing, communicating, the message” to see how they do, she said. “We’re trying to get the word out there that our research is deep, and we’ve been doing it since 2015.”

However, Scott Farnin, the legal counsel at consumer advocacy group Better Markets, said in a statement ahead of the SEC’s decision that the regulator should reject the bitcoin ETF applications outright, saying the surveillance-sharing agreements set up in proposals were “wholly inadequate.”

“The spot bitcoin markets (1) have a history of artificially inflated trading volumes due to rampant manipulation and wash trading; (2) are highly concentrated; and (3) rely on a select group of individuals and entities to maintain bitcoin’s network,” Farnin said. “These are features of the bitcoin network that make a proposed spot bitcoin-based ETP extremely vulnerable to manipulation by bad actors, posing unnecessary risks to investors and the public interest. The proposed rule changes offer little to neutralize these threats.”