TL;DR:
Morgan Stanley filed with the U.S. Securities and Exchange Commission an updated version of the S-1 form for its proposed Bitcoin Trust, designating Coinbase Custody and the Bank of New York Mellon (BNY) as custodians of the fund.
The amendment also establishes that BNY will act as fund administrator, transfer agent and cash custodian, while Coinbase will additionally serve as prime broker.

The custody structure outlined in the filing replicates traditional institutional standards. Bitcoin assets will be stored predominantly in cold storage vaults disconnected from the internet, which reduces exposure to potential hacks. A smaller portion of assets may be temporarily moved to operational wallets during ETF share creation or redemption processes. The document also clarifies that custody insurance exists but is distributed among multiple clients and may not cover the full extent of eventual losses.
For daily valuation, Morgan Stanley will use the CoinDesk Bitcoin Benchmark 4PM New York Settlement Rate, a rate that aggregates transaction data from major exchanges to establish the reference price of the asset.
Coinbase already operates as the primary custodian for the majority of approved Spot BTC ETFs in the United States, with Fidelity being the most notable exception. Morgan Stanley’s inclusion reinforces its dominant role in the infrastructure of listed crypto asset products. These funds have recorded unprecedented growth since their approval: BlackRock‘s IBIT accumulated multiple assets-under-management records since its launch in January 2024.

Morgan Stanley, the sixth-largest bank in the United States by total assets, manages approximately 20 ETFs, though only two carry its name directly. Analysts described the bank’s entry into the crypto asset market as a surprising move, given its historically limited exposure to this type of asset.