What is excess equity in a margin account?

Excess equity is the equity in the account above the total maintenance requirement on its holdings. It is the cushion before a margin call: the amount the account's value can lose, in dollars of equity, before the broker asks for more. It differs from buying power, which also depends on the opening requirement and the SMA.

How often should you check a margin account?

Whenever prices move sharply, and at least each time you add a position or the broker changes a requirement. The sums take a few minutes once the figures are written down. Brokers can raise a stock's requirement overnight, which can shrink excess equity without any change in price.

Is the broker's margin screen enough on its own?

It shows the current position well: equity, requirement and excess or deficit. It rarely shows how far prices can fall before a call, or which holding is doing the damage. Running the fall test yourself, for the whole account and for the largest positions, fills that gap.

Stock Margin Analyzer: How to Check a Margin Account

Q: Stock Margin Analyzer: How to Check a Margin Account

To analyze a margin account, take the market value of your stocks and the debit balance from the statement, work out equity and equity percentage, multiply each holding by its own maintenance requirement, and subtract the total from equity to get excess equity. Then solve for the fall in prices, for the whole account and for each large holding, that would bring a margin call.

How far can this account fall before the broker calls? Most margin screens don’t answer that. They show equity, a requirement and a cushion in dollars, all true for the prices of this instant, and leave the question that matters to you. A handful of sums on a statement will answer it.

Take a hypothetical account with two stocks and a loan. Stock A is worth $40,000, and the broker’s house requirement on it is 25%. Stock B is worth $20,000, with a 40% requirement because it’s more volatile. The debit balance is $25,000.

What do you own and what do you owe?

Two numbers from the statement. Long market value is the current value of the stocks: $60,000. The debit balance is the loan, including any interest posted to it: $25,000.

Equity is the difference. Equity percentage puts it in proportion.

That 58.3% is the headline figure. On its own it says little, because the call doesn’t come at one account-wide percentage. It comes when equity falls below the sum of each holding’s own requirement.

What does each holding require?

Multiply each position by its maintenance percentage. FINRA Rule 4210 sets a floor of 25% of market value for long stock, and each broker sets its own, usually higher, figure for every stock, so look up the one your broker applies to each holding. Stock margin requirements shows where to find them.

How much cushion is there?

Excess equity is equity minus the total requirement: 35,000 - 18,000 = $17,000. That is the margin of comfort in dollars. While it stays above zero, there’s no call.

How far can the whole account fall?

Suppose both stocks fall by the same percentage, x. The loan stays at $25,000 while the holdings and their requirements shrink together, so the call comes when what’s left after repaying the loan equals what the shrunken holdings require.

A 40.5% fall across the account brings a call. That’s a deep fall for a diversified portfolio, and a two-stock account is not diversified, which is why the next step matters more.

What if one stock does all the falling?

Run the same sum for each large holding on its own, holding the other steady.

The result runs against intuition. The volatile stock with the higher requirement can’t sink this account on its own: if B went to nothing, equity would be $15,000 against a $10,000 requirement on A. The steady, larger holding is the one to watch, because it carries most of the collateral and a 56.7% fall in it does the job. For a single position, the margin call calculator gives the call price directly.

Which fix rebuilds the cushion fastest?

If the cushion looks thin, there are three ways to rebuild it, and they don’t do the same amount of good. Compare putting $10,000 to work each way.

A deposit adds $10,000 to the cushion because it reduces the loan without touching the collateral, while a sale only frees up the requirement attached to whatever was sold, which is why selling a high-requirement stock helps more than selling a low-requirement one of the same value, even though both repay exactly the same amount of loan. Selling also turns a paper loss or gain into a real one. Weigh that before choosing.

What changes the answer?

Three things move these numbers without any trade on your part. A broker can raise a stock’s requirement, which lifts the total in Step 2 and cuts the cushion at once. Interest posted to the debit raises the loan a little every month. And a big holding getting bigger, through gains or new purchases, concentrates the account, which brokers often answer with a higher requirement on that name.

So rerun the sums whenever one of those happens. Write down the fall each holding can survive, set alerts well above the resulting prices, and keep maintenance margin in mind as a floor your broker can raise, never a figure it promises to keep. More on borrowing against stocks sits under margin, leverage and risk.