Margin Call

A margin call is triggered when the value of securities in a margin account declines to a point where the investor's equity — the market value of the securities minus the outstanding loan balance — falls below the broker's required maintenance margin. Under FINRA Rule 4210, the minimum maintenance margin for long equity positions is 25 percent of the current market value, though most major retail brokers set higher 'house' requirements, often in the 30–35 percent range.

When a margin call is issued, the investor typically has two to five business days to respond, though in rapidly declining markets a broker may demand immediate action or act unilaterally. To satisfy a margin call, the investor can: (1) deposit additional cash into the account, (2) deposit additional marginable securities as collateral, or (3) sell existing positions to reduce the loan balance and raise the equity ratio.

If the investor does not respond in time or the broker determines that rapid action is needed to protect the loan, the broker has the right — specified in the margin agreement — to sell securities in the account without the investor's consent or prior notice. The broker selects which securities to sell and is not required to choose the most tax-efficient or strategically optimal positions. This forced liquidation can result in selling at unfavorable prices, potentially at the bottom of a market decline.

The risk of forced liquidation is one of the most significant practical dangers of using margin. A sharp market decline can simultaneously reduce the value of margined securities and trigger margin calls across many investors at once, creating a self-reinforcing cycle in which forced selling drives prices lower, triggering further margin calls. This dynamic was observed during multiple historical market crises, including the 2008–2009 financial crisis and the March 2020 COVID-19 market disruption.

Investors using margin accounts should monitor their equity ratio continuously, understand exactly what their broker's house maintenance requirements are, and maintain a buffer of uninvested cash or unencumbered securities to meet potential margin calls without being forced to sell positions at inopportune times. The margin agreement, which investors must sign before a margin account is opened, discloses all relevant terms and the broker's liquidation rights.

Forced Liquidation: When a margin call goes unmet within the broker's required timeframe — or when a position declines so rapidly that the broker determines immediate action is necessary to protect the outstanding loan — the broker is contractually permitted under the margin agreement to liquidate account positions without the investor's prior authorization. This process is called forced liquidation, and it carries several features that can compound an investor's losses. The broker selects which securities to sell based on its own criteria, not necessarily the investor's tax preferences or strategic intentions; a long-held position with a large embedded gain may be sold alongside a position with a short-term loss, creating an unintended and potentially disadvantageous tax outcome. Furthermore, forced liquidations are executed as market orders, meaning they are filled at whatever price the market offers at the time of sale — during a fast-declining market, that price may be substantially below where the investor would have chosen to exit. Historical episodes such as the March 2020 market dislocation and the 2008 financial crisis both produced documented instances of widespread forced liquidations that drove certain securities further below their fundamental values before conditions stabilized.