BlackRock's tokenized U.S. Treasury fund, BUIDL, has reached a total size of approximately $1.83 billion. Ethereum leads with about $572 million, followed by BNB Chain at $502 million. Other significant allocations include Aptos with $307 million, Solana with $255 million, and Avalanche with $114 million. The BUIDL assets are primarily used in Ethena's USDtb stablecoin collateral structure, with Anchorage providing custody and compliance services.