Cboe’s BZX Exchange named crypto exchange Coinbase as the market for its surveillance-sharing agreement when it refiled its spot bitcoin exchange-traded (ETF) fund application on Friday.

Fidelity, WisdomTree, VanEck, Galaxy/Invesco and BlackRock all filed for spot bitcoin ETFs over the past few weeks, hoping to succeed at launching a product the U.S. Securities and Exchange Commission (SEC) has rejected for years.

On Friday, the SEC told some of these issuers that their applications were “inadequate” because they didn’t name the market that the fund sponsors are working with on their surveillance-sharing agreements, according to the Wall Street Journal.

In its refiled application, Cboe said Coinbase’s platform “represents a substantial portion of U.S.-based and USD denominated Bitcoin trading.”

“The Spot BTC SSA [surveillance-sharing agreement] is expected to have the hallmarks of a surveillance-sharing agreement between two members of the ISG, which would give the Exchange supplemental access to data regarding spot Bitcoin trades occurring on Coinbase if the Exchange determines it is necessary as part of its surveillance program for the Commodity-Based Trust Shares in a manner similar to the way that exchanges share information as part of ISG,” the filing said.

Read more: Bitcoin Tumbles on Report of SEC Saying Spot BTC ETF Filings Inadequate

The SEC has called for surveillance-sharing agreements with markets of “significant size” in the past, arguing that this is necessary to prevent market manipulation or other unwanted behaviors and protect consumers. The lack of these agreements figured heavily into many of the SEC’s prior rejections of bitcoin ETF applications.

The regulator still has to formally acknowledge it is reviewing the applications. The SEC will kick off an initial 45-day review period when it publishes the filings in the Federal Register – the national logbook – but can extend this to a total of 240 days.

Complicating the SEC’s calculus may be the fact that it sued Coinbase earlier this month on allegations of operating an unregistered securities exchange, broker and clearinghouse – though the SEC is not alleging that Bitcoin itself is a security, and SEC Chair Gary Gensler has often referred to it as an example of a digital asset that is not a security.

It also remains to be seen whether the SEC will agree that Coinbase is a significant, regulated market for bitcoin.

Read more: A Straightforward Explanation for Why Financial Giants Want to Issue a Spot Bitcoin ETF

UPDATE (June 30, 2023, 20:55 UTC): Adds additional detail.