Maintenance Margin Requirements: 25% Floor, Calls, and Portfolio Margin

Maintenance margin requirements set the minimum equity you must keep in a brokerage margin account while holding securities bought with borrowed money. FINRA Rule 4210 puts the federal floor at 25% of the current market value of securities held long, but most brokerages require 30% or more, and some demand much higher percentages on concentrated or volatile positions.¹ If your equity drops below your broker’s threshold, you face a margin call, forced liquidation, or both, often with little or no advance warning.

The 25% Federal Floor

FINRA Rule 4210 requires every margin account to hold equity equal to at least 25% of the current market value of long positions.¹ This is a floor, not a ceiling. No brokerage can let you hold less than 25%, but every brokerage can demand more.

The number is calibrated to absorb a meaningful price drop before the broker’s loan is at risk. In a volatile stock, though, 25% can evaporate in a single session, which is why most firms set their own bar well above the regulatory minimum.

Why Your Broker Likely Requires More

The margin agreement you signed when you opened your account gave the brokerage authority to set its own maintenance thresholds above the 25% floor. Most firms start at 30% as a baseline. These house requirements can change at any time, sometimes without advance written notice. A stock that carried a 30% requirement yesterday can carry 50% tomorrow if the firm reassesses its risk.

Concentrated positions attract the steepest add-ons. If a large portion of your account sits in one stock, the broker’s exposure jumps because a single bad earnings report could wipe out your portfolio. Firms run risk-based models that factor in historical volatility and how far the price would need to move before equity hits zero. Requirements of 50% to 70% are not unusual on heavily concentrated accounts or volatile individual names.

Brokerages may also restrict certain securities from being held on margin entirely. Stocks that don’t trade on a national exchange, micro-caps, and securities with extreme daily swings are common candidates. If your broker removes a stock’s margin eligibility while you already hold it on margin, you can face an immediate call to deposit cash or sell the position.

Calculating Your Margin Level

The math is straightforward. Take the current market value of your securities, subtract your margin loan balance, and you have your equity. Divide equity by total market value for your margin percentage.

Say you hold $10,000 worth of stock and owe $6,000 on the margin loan. Your equity is $4,000, and your margin level is 40%. If the stock falls to $8,000 while the loan stays at $6,000, equity drops to $2,000 and your level falls to 25%. You’re sitting exactly at the FINRA minimum, and almost certainly below the house requirement.

To find the dollar amount of equity your broker requires, multiply the total market value by the house maintenance percentage. If your broker requires 35% and your position is worth $8,000, you need $2,800 in equity. With only $2,000, you’re $800 short, and that’s the amount you need to deposit or free up by selling positions.

Different Rules for Short Sales and Non-Equity Securities

Short positions carry different maintenance requirements because losses on a short sale are theoretically unlimited. Under Rule 4210:

For stocks priced at $5 or above, you must hold the greater of $5 per share or 30% of current market value.
For stocks priced below $5, you must hold the greater of $2.50 per share or 100% of current market value.

The per-share minimums for cheap stocks are aggressive. A stock trading at $2 triggers a $2.50-per-share requirement, meaning you need to hold more equity than the stock is even worth.¹

Non-equity securities follow their own schedule. Investment-grade debt requires 10% of current market value. Municipal bonds require 7%. Other listed non-equity securities require 20% of market value or 7% of principal amount, whichever is greater. Leveraged ETFs fall under the standard 25% equity requirement because FINRA classifies them as equity securities, though most brokerages impose much higher house requirements on leveraged products.¹

What Happens If You Fall Below the Requirement

When equity drops below the maintenance level, you’re in a margin deficit. Many brokers will issue a margin call asking you to deposit cash or additional securities. The part that catches people off guard: your broker is not required to call you first.² Under most margin agreements, the firm can sell your securities immediately, without waiting, without asking which ones you’d prefer to keep, and without giving you time to deposit funds.

If your broker does give you time, the window is usually tight. You can meet the call three ways: deposit cash (a wire is fastest, since ACH transfers can take a few business days to clear), deposit additional marginable securities worth more than the deficit, or sell holdings to reduce the loan balance.³

Fail to act fast enough and the broker liquidates for you. The firm can sell enough to pay off the entire margin loan, not just enough to cover the call. You don’t get to choose what gets sold, sales happen at whatever price the market offers at that moment, and any trading costs come out of your account.³ While a call is outstanding, most firms will also restrict your ability to open new positions, effectively freezing the account for new buying until you resolve the deficiency.

There’s a worse outcome than a margin call, and most people underestimate it. If your securities decline far enough and fast enough, a forced liquidation might not cover the full amount you owe. You are personally responsible for any remaining balance on the margin loan, including accrued interest.² A sharp overnight gap down, a trading halt, or a broad market crash can leave your account with negative equity and a bill from the broker that exceeds every dollar you originally deposited.

Maintenance Margin Is Separate from Initial Margin

Don’t confuse the maintenance rule with the initial margin requirement. Under Federal Reserve Regulation T, you must put up at least 50% of the purchase price of any equity security you buy on margin.⁴ That’s a one-time test at the moment of purchase. Maintenance margin is the ongoing requirement that applies every day you hold the position. Satisfying the 50% initial requirement with room to spare doesn’t protect you: a decline in your holdings can push equity below the maintenance level and trigger a call within days or hours.

Portfolio Margin: An Alternative for Qualifying Accounts

Standard margin calculates requirements on each position individually, which can overstate the actual risk of a hedged or diversified portfolio. Portfolio margin, also authorized under Rule 4210, evaluates the risk of the entire account as a unit and often produces lower maintenance requirements for sophisticated, well-hedged strategies.

The eligibility bar is high. You must be approved for uncovered options trading, and your broker must provide a special written risk disclosure before your first portfolio margin trade. For accounts holding unlisted derivatives, FINRA requires a minimum equity of $5 million, which must be maintained at all times. If equity falls below $5 million, the broker cannot accept new opening orders starting on the fourth business day unless the shortfall is cured or the unlisted derivative positions are closed out.¹ Firms set their own minimum equity thresholds for portfolio margin accounts holding only listed securities and options, and those minimums vary.

New Intraday Margin Standards Starting in 2026

FINRA has overhauled its rules for active traders. Effective June 4, 2026, new intraday margin standards replace the pattern day trader framework entirely, including the familiar $25,000 minimum equity requirement that previously applied to anyone executing four or more day trades within five business days.⁵

Under the new approach, brokerages must monitor each margin account for “intraday margin deficits” whenever a transaction increases market exposure during the trading day. Instead of a fixed dollar threshold, the system focuses on whether the account holds enough equity relative to the risk it’s taking at any given moment.

If you run an intraday margin deficit and fail to cover it by the close of the fifth business day, and the broker determines you’re making a habit of it, your account will be restricted from opening new positions or increasing your debit balance for 90 calendar days. Small deficits under the lesser of 5% of account equity or $1,000 generally won’t trigger the penalty, and brokerages have discretion to excuse deficits caused by extraordinary circumstances.⁵

Firms have until October 20, 2027, to fully implement the new standards. During the transition, some brokerages may still apply the old pattern day trader rules while others adopt the new framework early. Check with your broker to find out which system currently applies to your account.⁶

1
FINRA. 4210. Margin Requirements
2
U.S. Securities and Exchange Commission. Margin: Borrowing Money To Pay For Stocks
3
FINRA. Know What Triggers a Margin Call
4
eCFR. 12 CFR 220.12 – Supplement: Margin Requirements
5
FINRA. Regulatory Notice 26-10: FINRA Adopts New Intraday Margin Standards to Replace the Day Trading Margin Requirements
6
U.S. Securities and Exchange Commission. Release No. 34-105226; File No. SR-FINRA-2025-017