REX Shares and Osprey Funds have officially filed applications with the U.S. Securities and Exchange Commission (SEC) for 21 single-asset cryptocurrency exchange-traded funds (ETFs). This large-scale filing marks one of the most ambitious pushes for crypto ETFs in U.S. history, covering assets such as Cardano (ADA), Stellar (XLM), Sui (SUI), and Hype (HYPE).