Crypto ETF issuer 21Shares has filed an S-1 form with the SEC for a proposed XRP ETF.The ETF, called 21Shares Core XRP Trust, would be listed on the Cboe BZX Exchange.The XRP held in the ETF would be custodied by Coinbase Custody Trust Company.Approval for an XRP ETF in the US remains uncertain due to ongoing legal battles between Ripple and the SEC.