Maintenance Margin — What It Means for Your Account

Maintenance margin is the minimum equity you must keep in a margin account to hold a leveraged position open. Drop below that floor and your broker issues a margin call: deposit more cash or watch positions get liquidated. FINRA sets the baseline at 25% of the position's market value, though most brokers hold you to more.

That is the maintenance margin meaning in one paragraph. The part that costs traders money is everything underneath it. The number is simple. The conditions that push you into a margin call are not, and they rarely show up when the screen is calm.

How maintenance margin works in a real account

When you trade on margin, the broker lends you part of the capital and your own equity covers the rest. Maintenance margin is the line your equity cannot cross while the position is open.

Equity is the position's current market value minus what you borrowed. As price moves against you, the market value falls, the loan stays fixed, and your equity shrinks. Once equity divided by market value drops under the maintenance requirement, the account is undermargined.

This is different from the deposit you put up to open the trade. The initial requirement gets you in. The maintenance requirement keeps you in. Both matter, and confusing them is where a lot of beginner accounts get into trouble.

Maintenance margin vs initial margin

Initial margin is the equity percentage you need to open a position. Under Regulation T, that is 50% for most stocks bought on margin. You put up half, the broker funds the other half.

Maintenance margin is lower. It is the percentage you must hold after the trade is live, and FINRA's floor is 25%. The gap between the two is your buffer. Price can move against you, your equity can fall from 50% toward 25%, and nothing happens until you reach the maintenance line.

The mistake is treating that buffer as free room. It is not free. It is the distance between a comfortable position and a forced exit, and volatility eats it faster than most traders expect.

A maintenance margin calculation example

Say you buy 100 shares at 100, a 10,000 position. With 50% initial margin you put up 5,000 and borrow 5,000. Your starting equity is 5,000, or 50%.

Now assume your broker's maintenance requirement is 30%. The price where you get a margin call is the loan divided by one minus the maintenance rate: 5,000 divided by 0.70, which is about 7,143. So your call price is roughly 71.43 per share.

Walk it through:

• At 71.43 the position is worth 7,143. Equity is 7,143 minus the 5,000 loan, or 2,143 — exactly 30% of market value.

• Drop one tick lower and equity falls under 30%. The broker issues a maintenance margin call.

A 28.6% move in the stock wiped out your buffer. That is the requirement working exactly as designed, and it is why the calculation is worth doing before the entry, not during the call.

What a margin call actually does to your position

A maintenance margin call is a demand to restore equity above the requirement. You meet it two ways: deposit cash or close positions until the account is back in compliance.

The part traders underestimate is the broker's right to liquidate without waiting for you. Account rules in most margin agreements let the firm sell your holdings to cover the shortfall, choose which positions to sell, and do it without a second notice. You are not promised any time to react.

This is where maintenance margin stops being an abstract percentage and becomes a real risk to the account. Forced liquidation tends to hit during fast, illiquid conditions — exactly when selling is most expensive. The buffer math holds in a quiet session. In a gap-down open or a volatility spike, price can blow through your call level before you ever see the notice, and the broker sells into the worst prices available.

Common maintenance margin mistakes beginners make

Most margin damage is not bad analysis. It is poor sizing against the maintenance buffer. A few patterns repeat:

• Sizing to the initial requirement and ignoring the maintenance line entirely, so a normal pullback triggers a call.

• Assuming the broker's rate matches FINRA's 25% floor, when the firm quietly holds you to 30% or 40% on the same stock.

• Treating the buffer as usable margin for a second position instead of protection for the first.

• Forgetting that requirements rise on volatile or concentrated holdings, shrinking the buffer without warning.

• Planning to meet a call with funds that take days to settle, while liquidation happens in minutes.

None of these are sophisticated errors. They are the result of looking at the entry and not the exit the requirement can force on you.

The takeaway on maintenance margin

Maintenance margin is the minimum equity that keeps a leveraged position open, set at 25% by FINRA and usually higher by your broker. It sits below the initial requirement, and the gap between them is the only buffer protecting you from a margin call.

The number is easy. The discipline is sizing so a routine move never reaches your call level, and never assuming you will get time to respond when it does. Margin is a tool, not free capital. The traders who survive it treat the maintenance line as a hard risk boundary, not a percentage to be tested.