BlackRock has amended its escrow agreement with Coinbase, updating the operating procedures for its iShares Bitcoin Trust ETF. According to a filing with the Securities Exchange Commission on September 16, the amendments to the Coinbase Prime Broker Agreement introduce changes aimed at improving the withdrawal process and asset management during unsettled transactions. The changes shorten the time Coinbase Custody takes to process withdrawals from Vault Balance to a public blockchain address (where trade credits have not yet been paid). The agreement also allows trusts to withdraw from Vault Balance or Trading Balance to a public blockchain address, provided that an amount equivalent to unpaid trade credits remains in the total balance after the withdrawal. According to the Securities Exchange Commission filing, the amendment updates Section 2.1 of the Custody Services Agreement. Coinbase Custody must now process withdrawals of digital assets to public blockchain addresses within 12 hours of receiving instructions from the trust or its authorized representative, subject to specific balance requirements. The development comes amid recent allegations against Coinbase that the exchange did not use BlackRock's funds to purchase actual bitcoins for the ETF. Social media rumors have it that Coinbase is issuing debt letters, rather than backing the 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 transactions.