On 16th September, the SEC approved interest payments on eligible cash posted as options margin, which previously earned clearing members nothing. The formula is the Fed reserve rate less a 0.10% annual fee, or 3.80% at the 17th September rate. OCC, the clearinghouse behind US listed options, reported roughly $2.5 billion in average cash margin during the year before its July filing. Applying 3.80% to that balance gives about $95 million a year, assuming it is eligible and rates and balances stay unchanged. OCC would owe the formula payment even if its own investments earned less. Moving cash to the Federal Reserve can reduce that potential gap. Safe custody alone does not ensure investment income covers the promised payment. The payments go to clearing members. The rule does not automatically promise the same interest to your brokerage account. OCC’s public filing table does not yet give a payment start date.