A screenshot of the document released by Bloomberg analyst James Seyffart on the The document description shows: Proposed rule changes for the listing and trading of iShares Ethereum Trust shares pursuant to Nasdaq Rule 5711(d) (Commodity-Based Trust Shares). According to the document, the proposed Ethereum ETF will use Coinbase Custody Trust Company as the custodian and will use the CME CF Ethereum USD reference rate.
James Seyffart said that according to public information, there are currently 5 spot Ethereum ETFs on file: Vaneck, ARKInvest/21Shares, Hashdex, Invesco US/Galaxy, and Grayscale's submission for converting ETHE (in no particular order).