Buying power in a Reg T margin account is a measure of how much you can purchase using your available funds and margin. It is important to understand how it is calculated and the factors that influence it.
- Basic Calculation:
- Buying Power = Available Funds × 4
- This calculation assumes you are buying marginable securities with a 25% initial margin requirement during Regular Trading Hours.
- Buying Power = Available Funds × 4
- Available Funds Calculation:
- Available Funds = Equity with Loan Value (ELV) - Initial Margin
- Equity with Loan Value (ELV): The total value of your account, including cash, securities, and any margin loan.
- Initial Margin: The minimum amount of equity you must maintain to open a new position.
- Available Funds = Equity with Loan Value (ELV) - Initial Margin
- Real-time Available Funds Calculation:
- IBKR uses a credit check formula: "Lesser of (current Equity with Loan Value or Previous Day's Equity with Loan Value) Minus (Total Initial Margin requirements + Initial margin of new order)"
- Intraday vs. Overnight Buying Power:
- Intraday Buying Power: Generally 4 times the Available Funds for assets with a 25% margin requirement.
- Overnight Buying Power: Based on the Special Memorandum Account (SMA), calculated as 2 times the SMA value. This is because the Reg T requirement for stocks held overnight is 50%.
- Factors Affecting Buying Power:
- Previous Day's Equity with Loan Value (snapshot taken at 16:15 EST the prior day)
- Current Equity with Loan Value
- Initial Margin Requirements (which vary by security)
- Account type (e.g., Pattern Day Trader accounts have additional restrictions)
- IBKR's "Concentrated Margin" calculation may increase initial margin requirements
- Important Considerations:
- Only funds in the Securities segment are included in Available Funds for securities Buying Power.
- Initial Margin requirements are calculated even when you are not borrowing funds or using cash for purchases.
- As capital is used for trades, available buying power decreases.
- Orders are accepted only if there are sufficient Available Funds to meet the margin for all open positions and the new order.
- Checking Your Buying Power:
- Log in to your account and check the Account Window or Account tab.
- Use the check margin/preview function in the trading platform for real-time margin status.
It is crucial to note that while the general calculation suggests a 4:1 leverage, the actual buying power may vary based on the specific securities traded and held in the account, as well as individual account restrictions.
Additional Information