Excess Margin Deposit Defined

What Is an Excess Margin Deposit?

An excess margin deposit is the collateral held in a margin account that is in excess of the minimum level required to maintain that account's good standing. Margin traders who fail to maintain excess margin deposits may find themselves subject to margin calls.

Understanding Excess Margin Deposits

In the United States, Regulation T of the Federal Reserve governs the initial deposits necessary to establish a margin trading account. Similarly, the Financial Industry Regulatory Authority (FINRA) is responsible for regulating margin maintenance requirements, which are the minimum levels of collateral required in margin accounts. The value of collateral in a margin trading account that exceeds these regulatory requirements is known as the account's excess margin deposit.

According to Regulation T, a margin trader is able to borrow up to 50% of the purchase price of a stock, provided that that stock is itself eligible for trading on argin. Some stocks, such as securities with very small market capitalizations, may be barred from margin trading altogether.

This 50% level is known as the initial margin. However, individual brokerage firms have the discretion to adjust this rule provided their own standards are more stringent than those of Regulation T. For example, a broker would be permitted to employ 30% as their initial margin, but they would not be allowed to use a more aggressive standard, such as 70%.

Once a stock has been purchased on margin, FINRA regulations require that the collateral deposited in the margin account does not fall below 25% of the market value of the securities purchased. Here again, brokerage firms have the flexibility to adjust their requirements as long as their standards are more stringent than those required by FINRA, such as 35% instead of 25%.

Real World Example of an Excess Margin Deposit

To illustrate, consider a scenario in which an investor purchases $20,000 worth of securities. To finance the purchase, the investor borrows $10,000 from their brokerage firm using a margin trading account. To support this purchase, the investor deposits an additional $10,000 into the account to act as collateral.

If the market value of the securities falls to $18,000, the equity in the investor's margin account would decline to $8,000 ($18,000 worth of stocks minus the $10,000 loan). If the investor's brokerage firm has a maintenance requirement of 25%, then the investor's account would need to have at least $4,500 of equity in order to remain in good standing (25% of $18,000). Since the $8,000 of equity is greater than the maintenance requirement of $4,500, the investor's margin account is still in good standing.

The excess margin deposit, in this case, is therefore $3,500 ($8,000 of equity minus the $4,500 maintenance requirement).