Hashdex, a crypto asset management firm, has filed an S-1 registration statement with the U.S. Securities and Exchange Commission (SEC) for an ETF that would hold Bitcoin (BTC), Ether (ETH), and potentially other assets. The proposed ETF, called the Hashdex Nasdaq Crypto Index US ETF, aims to initially include BTC and ETH, with the possibility of adding more assets as regulatory conditions evolve