What Is a Maintenance Requirement for Margin Accounts?

The maintenance requirement on a margin account is the minimum equity you must keep in the account after buying securities with borrowed money. FINRA Rule 4210 sets the regulatory floor at 25% of the current market value of the securities held long.¹ Fall below that line and your broker can sell your holdings to cover the shortfall, often without calling you first.

How the 25% Floor Works

Equity is the market value of your holdings minus what you owe the broker (the debit balance). Buy $40,000 of stock with $20,000 of your own money and a $20,000 margin loan, and your equity is $20,000, or 50% of market value. If the stock falls to $28,000, your equity drops to $8,000, roughly 28.6%. Still above the 25% floor, but the cushion is thin.

The 25% figure is the standard for equity positions. Other holdings have their own maintenance percentages under Rule 4210:

Investment-grade corporate bonds: 10% of current market value.²
Municipal bonds and other exempt securities: 7% of current market value.²
Security futures contracts: 20% of current market value.²

These are floors. Your brokerage can require more; it cannot require less.

One quick boundary worth naming: some securities cannot be margined at all. Stocks that don’t meet exchange listing standards, certain low-priced equities, and newly issued shares during their initial trading period require 100% of the purchase price upfront.³ You can hold them in a margin account, but they generate no borrowing power.⁴

Calculating the Price That Triggers a Call

To find the exact price where the 25% floor is breached, divide your debit balance by 0.75.

Say you bought $20,000 of stock, put up $10,000 of your own money, and borrowed $10,000. Your debit balance stays at $10,000 (ignoring interest) regardless of what the stock does. Divide $10,000 by 0.75 and you get about $13,333. At that market value, your equity is $3,333, exactly 25%. Below $13,333, you’re in margin call territory.¹

If your broker uses a 30% house requirement instead of 25%, divide by 0.70. In the same example, the trigger rises to about $14,286. The higher the requirement, the sooner the call.

Short Sales Have Their Own Numbers

For short stock positions, the maintenance requirement depends on price:

Stocks at $5.00 or above: the greater of $5.00 per share or 30% of current market value.²
Stocks below $5.00: the greater of $2.50 per share or 100% of current market value.⁵

The per-share dollar minimums on cheap stocks bite hard. A $1.00 short triggers a $2.50-per-share maintenance requirement, or 250% of market value, which effectively prices margin traders out of shorting penny stocks.

Your Broker’s House Requirement Is the One That Governs You

Every major brokerage sets its own maintenance levels above the FINRA floor. Common house requirements sit at 30% or 40%, and they climb from there for volatile stocks, thinly traded names, or concentrated positions.² A biotech stock that swings 10% a day might carry a 50% or higher requirement, and firms can set 100% on securities they consider too risky to lend against at all.

Rule 4210 requires firms to review whether higher margins are appropriate for securities subject to rapid price changes, illiquid markets, or positions too large to liquidate quickly.² House requirements can also change without your involvement. You might open a position under a 30% requirement and find it raised to 50% because the firm reassessed the risk. Your margin agreement grants that discretion.

Check your account’s specific house requirements before assuming the 25% number applies to you. It almost certainly doesn’t.

What Happens When You Fall Below

The common assumption is that the broker will call, explain the shortfall, and wait for you to deposit cash. That is not how the rules work. Your broker is not required to contact you before selling securities to cover a margin deficiency, and FINRA guidance is direct on this: firms can liquidate without issuing a call, and they can sell enough to pay off the entire margin loan, not just enough to cure the shortfall.⁶

Many firms do issue margin calls as a courtesy and give you a window to act. Nothing in the rules requires it. The agreement you signed when opening the account almost certainly gives the firm full discretion over which securities to sell, when, and how much. On sharp down days, some firms issue intraday calls and may liquidate before the closing bell.⁶

Ways to Cure a Margin Call

If your broker does give you time, three options bring the account back into compliance:

Deposit cash by wire or transfer to cover the deficiency.
Sell securities to reduce the debit balance.
Transfer in fully paid-for securities from another account to raise equity.

Cash is the cleanest option because it avoids forced selling at depressed prices. But the timing pressure is real. If the market keeps falling between the notice and settlement, the deficiency can grow.

You Can Owe More Than You Deposited

In extreme cases, holdings can drop below the loan balance and leave you with negative equity. A cash account limits your loss to what you deposited; a margin account does not. If a stock bought on margin goes to zero, you still owe the loan. The broker will liquidate what it can and pursue you for the remainder.

Pattern Day Traders Face a Separate Rule

If your broker classifies you as a pattern day trader, a different maintenance standard applies alongside the ordinary one. Under the current version of Rule 4210, a pattern day trader must keep at least $25,000 in equity in the account at all times, and that equity must be in place before day trading resumes.⁷

Miss a day-trading margin call and fail to meet it within five business days, and the account gets restricted to cash-only transactions for 90 days or until the call is satisfied.² That restriction is separate from, and more forgiving than, what a standard maintenance margin call can trigger, which is immediate liquidation. FINRA has proposed replacing this framework with intraday margin standards, but as of early 2026 the proposal is still under review and the existing $25,000 rule remains in force.⁷

The practical takeaway sits above any single percentage. Know your broker’s house requirement, calculate the price at which your position hits it, and watch that number the way you’d watch a stop-loss. The 25% figure is where regulators draw the line. Your broker will draw it earlier, and it doesn’t have to warn you when you cross.

1
Securities and Exchange Commission. Notice of Filing of Proposed Rule Change Relating to FINRA Rule 4210 Margin Requirements
2
FINRA. 4210. Margin Requirements
3
eCFR. Part 220 Credit by Brokers and Dealers (Regulation T)
4
FINRA. Margin Regulation
5
FINRA. Regulatory Notice 11-15 Guidance on Low-Priced Equity Securities in Customer Margin and Firm Proprietary Accounts
6
FINRA.org. Know What Triggers a Margin Call
7
Federal Register. Notice of Filing of a Proposed Rule Change To Amend FINRA Rule 4210 Margin Requirements To Replace the Day Trading Margin Provisions With Intraday Margin Standards