Depositing $100 million into a bank account is legally and technically possible, but it triggers immediate and rigorous regulatory scrutiny. Financial institutions are mandated by federal law and anti-money laundering frameworks to file extensive Currency Transaction Reports and Suspicious Activity Reports for extraordinarily large deposits. The account holder must provide comprehensive documentation verifying the lawful source of the funds—such as corporate sales, inheritances, or asset liquidations—before the bank will accept and clear the transfer.