I wonder if a representative from IB could confirm the following points: (1) When money is held in the commodities account as margin for open futures contracts, such money is not covered by SIPC or IB's Lloyd's policy. Only after the futures positions have been squared and the balance is transferred back to the securities account will investor protection applies. http://www.interactivebrokers.com/en/trading/accountProtection.php (2) When money is held in the commodities account as margin for open futures contracts, such money continues to receive interest but is treated separately from the balance in the securities account, ie, the two balances are not aggregated for the purpose of determining applicable tiered interest rates. http://www.interactivebrokers.com/en/accounts/fees/interest.php Thanks!