BlackRock, the world’s largest asset manager, filed a preliminary prospectus with the U.S. Securities and Exchange Commission on Monday for a new Bitcoin exchange-traded fund that pairs exposure to the iShares Bitcoin Trust ETF with limited downside protection.

The proposed iShares Bitcoin Managed Protection ETF, referred to as PBIT, would use options linked to BlackRock’s existing spot Bitcoin ETF, IBIT, rather than holding Bitcoin directly. IBIT, which holds Bitcoin in custody and trades on brokerage platforms, held $65.7 billion in net assets as of Monday, according to BlackRock’s filing.

PBIT would employ three overlapping tranches of options contracts that are periodically replaced to maintain exposure while capping potential gains and limiting losses. Each tranche initially targets a maximum loss exposure of about 10% to the underlying Bitcoin-linked asset before fees and expenses, though the fund does not guarantee a fixed floor or cap value, meaning losses could exceed the stated threshold.

The filing marks BlackRock’s third Bitcoin ETF submission. Earlier offerings include the iShares Bitcoin Premium Income ETF, launched in June 2026, and the iShares Staked Ether Trust ETF, introduced in March 2026. The company also operates the iShares Ethereum Trust ETF, which held $8 billion in assets as of the filing date.

BlackRock has not pursued spot ETFs for cryptocurrencies beyond Bitcoin and Ethereum, such as Solana or XRP. Nate Geraci, president of ETF Store, noted the firm’s focus appears confined to BTC and ETH, a stance he highlighted on social media.

The move reflects growing institutional interest in structured crypto products that balance risk and return, though regulators have yet to approve direct spot ETFs for alternative digital assets.