Glossary
Maintenance margin
The minimum equity that must be kept in a margin account, at least 25% under FINRA rules; falling below it triggers a margin call.
On this page
Maintenance margin is the minimum amount of your own equity that must stay in a margin account after a purchase, expressed as a percentage of the current market value of the securities. Initial margin governs how much you can borrow to open a position; maintenance margin governs how far prices can fall before the broker demands more money. Under FINRA Rule 4210 the floor for long stock positions is 25%, and as of 2026 that requirement applies throughout the trading day.
How it works
Equity is the market value of your securities minus what you owe the broker. If equity falls below the maintenance percentage, you get a maintenance call. Brokers can and often do set higher house requirements, commonly 30% to 40%, and more for volatile, concentrated or low-priced stocks, and they can raise them without notice.
What to watch for
The higher the house requirement and the more you borrow, the smaller the price drop needed to trigger a call. Short positions carry their own, higher maintenance requirements. Brokers are not required to warn you before selling securities to restore the minimum, so knowing your trigger price in advance is part of managing a margin account.