BlackRock, the world’s largest asset manager, has filed a preliminary prospectus with the US Securities and Exchange Commission (SEC) for a new exchange-traded fund (ETF) aimed at providing Bitcoin exposure with built-in downside protection and capped returns. Named the iShares Bitcoin Managed Protection ETF (PBIT), the proposed fund would not hold Bitcoin (BTC) directly but would instead use options linked to the iShares Bitcoin Trust ETF (IBIT), BlackRock’s existing spot Bitcoin ETF.