According to a filing with the Securities Exchange Commission (SEC) on Friday, Fidelity applied to register the "OnChain" stock class for its tokenized dollar money market fund Fidelity Treasury Digital Fund (FYHXX), which was launched late last year and holds cash and U.S. Treasury securities. According to the relevant documents, the "OnChain" category of the FYHXX fund shows that it currently uses the Ethereum network and may expand to other blockchains in the future. The registration is subject to regulatory approval and is expected to take effect on May 30.