: This is the critical figure that forms the basis for your buying power; it is the sum of your cash and the market value of your marginable securities.

: In a cash account, your buying power is simply your settled cash . Key Rules and Restrictions Equity with Loan Value - IBKR Campus

: For standard margin accounts that are not flagged as PDT, buying power is usually 2x your equity .

: This is typically 4x your maintenance margin excess from the previous day's close for Pattern Day Traders (PDT).