Golden Finance reported that BlackRock has amended its custody agreement with Coinbase and updated the operating procedures of its iShares Bitcoin Trust ETF. According to a document submitted to the U.S. Securities and Exchange Commission on September 16, the amendment to the Coinbase Prime Broker Agreement introduced some changes aimed at improving the withdrawal process and asset management during unsettled transactions. These modifications shorten the time Coinbase Custody takes to process withdrawals from Vault Balance to a public blockchain address (while trade credits have not yet been paid). The agreement also allows the trust to withdraw from Vault Balance or Trading Balance to a public blockchain address, provided that an amount equivalent to the unpaid trade credit remains in the total balance after the withdrawal. According to the SEC document, the amendment updates Section 2.1 of the Custody Services Agreement. Coinbase Custody must now process the withdrawal of digital assets to a public blockchain address within 12 hours of receiving instructions from the trust or its authorized representative, subject to specific balance requirements. This development occurred amid recent allegations against Coinbase that the exchange did not use BlackRock's funds to purchase actual Bitcoin for the ETF. Social media rumors have claimed that Coinbase is issuing debt letters instead of backing an ETF with Bitcoin and using BlackRock’s funds to manipulate the price of Bitcoin. These contract updates may also address regulatory expectations and best operating practices, with a focus on reducing withdrawal processing times and ensuring asset availability during unsettled trades.