Deribit's new fee structure will be implemented starting November 1. The first-tier fee discount requires having 100K USDC in your account, with no trading volume requirements. Currently, USDC has an annualized interest rate of 4.1%. On October 1, accounts will receive a predicted fee rate based on September's trading volume. If it's lower than the current rate, the account will automatically upgrade in October; if it's higher, it will be reassessed and implemented in November.