Few phrases strike as much concern into an investor’s day as “margin call.” For traders using leverage, understanding exactly how margin calls work isn’t optional — it’s essential knowledge that can mean the difference between navigating a market downturn calmly and being forced into a poorly timed, costly sale.
Margin calls are one of the most misunderstood aspects of leveraged trading. Many new investors know the term exists but don’t fully understand the mechanics behind it: what triggers a margin call, how brokers calculate the thresholds involved, and what options are actually available once one occurs.
This guide walks through the entire process in detail — from how margin accounts function in the first place, to what happens step by step when a margin call is triggered, to the strategies experienced traders use to avoid them altogether.
“A margin call isn’t a punishment — it’s math catching up with a position that no longer has enough cushion behind it.”
— Infinity Capital Group
A Quick Refresher: How Margin Accounts Work
Before diving into margin calls specifically, it helps to revisit how margin accounts function. When you trade on margin, you’re borrowing money from your brokerage to purchase securities, using your existing account holdings as collateral for that loan.
This arrangement allows you to control a larger position than your own capital would normally support. If your investments rise in value, your gains are calculated on the full position size — not just the portion you funded yourself — which can significantly boost your returns. But if your investments decline, your losses are similarly magnified.
Because the brokerage has lent you money and is exposed to risk if your position loses value, margin accounts come with ongoing requirements. You must maintain a certain level of equity relative to the value of your borrowed position at all times. This is where margin calls come into play.
What Exactly Is a Margin Call?
A margin call occurs when the equity in your margin account falls below the minimum maintenance requirement set by your brokerage. In simple terms, it’s a notification from your broker that your account no longer has enough value to safely support the amount you’ve borrowed, and you need to take action to fix it.
When this happens, you generally have two options: deposit additional cash or securities into your account to restore the required equity level, or sell some of your holdings to reduce the size of your position and pay down the borrowed balance.
If you fail to act, or don’t act quickly enough, your broker has the legal right to sell your securities on your behalf — often without further notice — to bring your account back into compliance. This is one of the most important and least understood aspects of margin trading: the decision to sell may not ultimately be yours to make.
Initial Margin vs. Maintenance Margin
To understand margin calls fully, it’s important to distinguish between two related but different concepts: initial margin and maintenance margin.
Initial margin refers to the minimum amount of your own capital required to open a leveraged position in the first place. This is typically expressed as a percentage of the total purchase price — for example, being required to fund 50% of a trade with your own money while borrowing the rest.
Maintenance margin, on the other hand, is the minimum amount of equity you must continue to hold in your account after the position is open, expressed as a percentage of the total position value. This threshold is usually lower than the initial margin requirement, but it must be maintained continuously for as long as you hold the leveraged position.
It’s the maintenance margin requirement that triggers margin calls. As long as your account equity stays above this threshold, no action is required. But if the value of your holdings declines enough that your equity falls below it, a margin call is triggered.
How Brokers Calculate Margin Call Triggers
Understanding the actual math behind a margin call can make the concept feel far less abstract. While specific formulas vary slightly between brokerages, the underlying principle remains consistent.
Your account equity is calculated as the total market value of your holdings minus the amount you’ve borrowed. Your broker then compares this equity figure to the maintenance margin requirement, usually expressed as a percentage of your total position value.
For example, if a brokerage requires 25% maintenance margin, your equity must remain at or above 25% of your total position value at all times. If the value of your holdings drops enough that your equity falls below that 25% threshold, a margin call is triggered automatically — often through the brokerage’s own monitoring systems, which track account values continuously throughout each trading session.
It’s worth noting that maintenance margin requirements aren’t always static. Some securities are considered riskier or more volatile than others, and brokers may apply higher maintenance requirements to those positions. Additionally, brokerages can adjust margin requirements during periods of extreme market volatility, sometimes with little advance notice.
“The threshold that protects your broker’s loan is the same threshold that can force your hand as an investor.”
— Infinity Capital Group
What Triggers a Margin Call in Practice
While the underlying mechanics involve equity percentages and maintenance thresholds, margin calls in practice are almost always triggered by one thing: a decline in the value of the securities held in a leveraged account.
This decline can happen gradually, over the course of days or weeks, as a position slowly loses value. Or it can happen suddenly, during a sharp single-day market drop, an unexpected company announcement, or a broader market shock. The speed at which a margin call occurs often depends on the speed of the underlying price movement.
It’s also possible for a margin call to be triggered indirectly, even if the specific position you’re most focused on hasn’t declined. If other holdings in the same margin account lose value, your overall account equity can fall below the maintenance threshold, triggering a call even on positions that haven’t moved.
This is an important nuance many traders overlook: margin calls are calculated at the account level, not necessarily the individual position level, meaning that weakness in one part of a diversified margin account can still create pressure across the entire account.
What Happens When You Receive a Margin Call
When a margin call is triggered, your broker will typically notify you — through email, a phone call, an account alert, or a combination of these — informing you that your account equity has fallen below the required maintenance level and specifying the amount needed to restore compliance.
At this point, you generally have a limited window of time to respond, which can range from the same trading day to a few business days, depending on your brokerage’s specific policies and the severity of the shortfall. It’s essential to understand your specific broker’s margin call policies in advance, since timelines can vary significantly.
You typically have several options for responding to a margin call. You can deposit additional cash into your account to increase your equity. You can deposit additional marginable securities, which can also count toward restoring your equity level. Or you can sell some of your existing holdings, using the proceeds to pay down your borrowed balance and reduce your account’s overall leverage.
Whichever option you choose, the goal is the same: bring your account equity back above the maintenance margin threshold before the deadline set by your broker.
What Happens If You Don’t Respond in Time
This is perhaps the most critical part of understanding margin calls — and the part that catches many traders off guard. If you don’t respond to a margin call within the specified timeframe, or if the shortfall is significant enough, your broker has the legal right to sell securities in your account without further notice or consent.
This is often referred to as a forced liquidation, and it’s a right that’s typically outlined in the margin agreement you sign when opening a margin account — meaning it’s not a surprise policy, but a contractual term investors agree to in advance, often without fully appreciating its implications.
Forced liquidations can be particularly painful for several reasons. First, your broker chooses which securities to sell, not you — meaning positions you’d prefer to hold may be sold instead of ones you’d be more willing to part with. Second, these sales often happen during periods of market decline, meaning you may be forced to sell at or near the lowest prices, locking in losses that might have recovered given more time. Third, in fast-moving markets, brokers may liquidate more than the minimum necessary to restore compliance, in order to provide a buffer against further declines.
This combination of factors — losing control over which assets are sold, selling during unfavorable price conditions, and potentially losing more than strictly necessary — is why margin calls are considered one of the most significant risks of leveraged trading.
“Once a margin call goes unanswered, control over the outcome shifts from the investor to the broker.”
— Infinity Capital Group
A Simplified Example of a Margin Call
To make the mechanics more concrete, consider a simplified example. Suppose an investor uses margin to purchase securities worth a total value significantly greater than their own cash contribution, borrowing the difference from their broker. Their brokerage requires 25% maintenance margin on the position.
As long as the investor’s equity — the value of the securities minus the borrowed amount — stays at or above 25% of the total position value, no margin call occurs. But if the value of the securities declines significantly, the investor’s equity shrinks much faster than the total position value, since the borrowed amount stays fixed while the underlying asset value drops.
Once the investor’s equity falls below the 25% threshold, a margin call is triggered. The investor must then either deposit additional funds to restore their equity above 25%, or sell part of their position to reduce the total value being financed with borrowed money.
This example illustrates a key point: because the borrowed portion of a margin position doesn’t shrink when prices fall, even a moderate decline in the underlying investment can translate into a much larger percentage decline in the investor’s actual equity — which is exactly why margin calls can happen faster than many traders expect.
Why Margin Calls Often Happen During Volatile Markets
Margin calls tend to cluster during periods of high market volatility, and understanding why can help investors better anticipate and prepare for them.
During sharp market declines, asset values can fall quickly, pushing account equity below maintenance thresholds in a short period of time. Because these declines often affect many securities simultaneously — particularly during broad market sell-offs — investors holding diversified margin positions may find multiple holdings losing value at once, compounding the impact on overall account equity.
Volatile markets can also lead brokerages to raise maintenance margin requirements on certain securities, especially those experiencing unusually large price swings. This means that even without a decline in the value of your holdings, a sudden increase in required maintenance margin can itself trigger a margin call.
This combination — falling asset values and potentially rising margin requirements — is why margin calls tend to be most common, and most severe, during exactly the periods when markets are already under stress and investor emotions are running highest.
Strategies for Avoiding Margin Calls
While margin calls can never be entirely eliminated as a possibility when using leverage, several strategies can significantly reduce the likelihood of encountering one.
Maintaining a substantial equity cushion above the minimum maintenance requirement is one of the most effective approaches. Rather than borrowing up to the maximum amount allowed, using only a portion of available margin leaves room to absorb price declines without immediately triggering a call.
Diversification also plays a role in managing margin call risk. Concentrating a leveraged position in a single security or a small handful of correlated holdings increases the chances that a single adverse price movement will trigger a call. Spreading leveraged exposure across a broader range of assets can help reduce this concentration risk.
Monitoring your account regularly is equally important. Rather than waiting for a margin call notification, proactively tracking your account equity relative to maintenance requirements allows you to take corrective action — depositing funds or reducing position size — before a formal margin call is triggered.
Setting personal risk thresholds that are more conservative than your broker’s official maintenance requirements can also provide an additional buffer. For example, choosing to take action if your equity approaches 35% of position value, even if your broker’s official threshold is 25%, gives you more room to respond calmly rather than reactively.
“The best way to handle a margin call is to build your account so you never actually receive one.”
— Infinity Capital Group
What to Do If You Receive a Margin Call
If a margin call does occur, having a clear, calm plan can make a significant difference in the outcome. The first step is understanding exactly how much additional equity is required and by when, which your brokerage should specify clearly in its notification.
From there, evaluate your available options. If you have accessible cash or marginable securities outside your account, depositing funds may be the most straightforward way to restore compliance without disrupting your existing positions.
If additional funds aren’t available, carefully consider which positions to sell in order to reduce your leveraged exposure. Rather than reacting under pressure, this is where having a predetermined plan — decided before a margin call ever occurs — can be invaluable, since it allows you to make decisions based on strategy rather than panic.
Above all, it’s important to act promptly. Delaying a response to a margin call doesn’t make the underlying problem go away — it simply increases the risk that your broker will step in and liquidate positions on your behalf, potentially at less favorable terms than you could have achieved by acting first.
The Emotional Side of Margin Calls
Beyond the technical mechanics, margin calls often carry a significant emotional weight that shouldn’t be underestimated. Receiving a margin call notification, particularly during a stressful market environment, can trigger anxiety and pressure to make quick decisions.
This emotional pressure is precisely why preparation matters so much. Investors who understand margin call mechanics in advance, who maintain conservative equity cushions, and who have a predetermined plan for how they’ll respond, tend to navigate these situations with far more composure than those encountering the concept for the first time in the middle of a market downturn.
Recognizing that margin calls are a normal, built-in feature of leveraged trading — rather than a sign of personal failure — can also help investors respond more rationally, focusing on the practical steps needed to resolve the situation rather than becoming paralyzed by stress.
Is Margin Trading Worth the Risk of Margin Calls?
Ultimately, whether margin trading is worth the added risk of margin calls depends heavily on an individual investor’s experience, risk tolerance, and financial situation. For experienced traders with strong risk management practices, the potential benefits of leverage may outweigh the added complexity and risk of margin calls.
For newer investors, or those who prefer a more conservative approach, avoiding margin altogether — and the possibility of margin calls entirely — often provides a simpler, more predictable path toward long-term investing goals.
There’s no universally correct answer. What matters most is that any decision to use margin is made with a full understanding of how margin calls work, what triggers them, and what the consequences of an unanswered call can be.
Final Thoughts
Margin calls are one of the most important mechanics to understand before engaging in leveraged trading. They exist to protect brokerages from the risk of lending money against declining collateral, but they also place real financial pressure — and real consequences — on investors who don’t manage their leveraged positions carefully.
Understanding exactly how maintenance margin requirements work, what triggers a call, and what your options are once one occurs can make the difference between navigating a market downturn with a clear plan and being forced into an unfavorable, broker-initiated liquidation.
At Infinity Capital Group, we believe that leverage can be a legitimate tool for experienced investors, but only when paired with a thorough understanding of the risks involved. Margin calls aren’t something to fear blindly — they’re something to understand, prepare for, and manage with discipline.