IBKR Margin Cushion Alert Setup: Mobile & TWS (2026)

About this guide: I'm Lawrence, the writer behind supa.is. Between February and May 2026 I've published 150+ articles on supa.is across crypto and brokerage tooling — including 30+ Interactive Brokers-specific guides (recent examples: IBKR Bracket Order Setup, IBKR Desktop vs TWS, IBKR Paper Trading Setup). The most-repeated reader question across that IBKR archive is exactly how to configure margin cushion alerts without getting overwhelmed by TWS settings, which is why I'm publishing this standardized guide instead of answering one-off.

Note: Steps below are reconstructed from official docs and platform UI. Verify each step against the current UI before relying on it.

If you trade on Interactive Brokers (IBKR), margin is your lifeline—and your biggest enemy. A sudden gap down in a stock, a spike in volatility, or a margin rate adjustment can turn a healthy account into a margin call within minutes.

The difference between a professional trader and a blown account often comes down to one setting: the Margin Cushion Alert.

IBKR provides this built-in risk management tool across both the Trader Workstation (TWS) and the IBKR Mobile app. It monitors your account's margin utilization in real-time and sends you an alert before you hit the liquidation threshold. But if you've ever opened the TWS alerts menu, you know it's a labyrinth of checkboxes.

This guide cuts through the noise. We'll walk you through exactly how to set up margin cushion alerts on both TWS and the mobile app, how to calibrate the percentage to your trading style, and why relying on the default settings is a recipe for disaster in 2026.

What Is the IBKR Margin Cushion Alert?

Before we click through the menus, it's crucial to understand what the margin cushion alert actually measures.

When you trade on margin, IBKR calculates your margin requirement—the minimum amount of equity you must maintain in your account. If your equity drops below this requirement, IBKR will issue a margin call. If you don't deposit funds or liquidate positions, IBKR will liquidate your positions at their discretion, often at the worst possible price.

The margin cushion alert is a proactive warning system. You set a percentage threshold (e.g., 10%). IBKR continuously calculates your Excess Liquidity (Net Liquidation Value minus Margin Requirement) and divides it by your Net Liquidation Value.

If your margin cushion drops below your set percentage, the alert triggers.

Why this matters: By the time you receive a margin call, it's often too late to react calmly. The market might be gapping against you, and your liquidity might be evaporating. The margin cushion alert gives you a buffer—usually 15 to 30 minutes of warning time depending on market conditions—to reduce your position size or add capital before the margin call triggers.

How to Set Up Margin Cushion Alerts in TWS

TWS is the powerhouse of IBKR, but its alert system is notoriously buried. Here is the exact path to configure your margin cushion alert.

Launch TWS.
In the top menu bar, click Alerts.
Select Account Alerts from the dropdown menu.

Step 2: Configure the Margin Cushion Threshold

In the Account Alerts window, look for the Margin Cushion section.
You will see a checkbox labeled Margin Cushion. Check this box to enable the alert.
Next to it, you'll find an input field for %. This is your threshold.

Step 3: Calibrate Your Percentage

This is the most critical step. What number should you put in the % field?

Aggressive Traders (Day Trading / Scalping): 5% to 10%. You are used to high turnover and tight margins. You want to be alerted only when the situation is genuinely critical, avoiding alert fatigue.
Swing Traders: 15% to 20%. You hold positions overnight. Overnight gaps can wipe out a 5% cushion in seconds. A 15-20% buffer gives you time to react in the morning or during pre-market.
Conservative Investors: 30% to 50%. You want maximum early warning. If your cushion drops to 30%, you'll know the market is moving against you well before you are in danger of liquidation.

*Recommendation:* If you are unsure, start with 20%. It provides a robust safety net without triggering you every time the market twitches.

Step 4: Set the Alert Frequency and Delivery Method

Below the percentage field, you will see options for Alert Frequency (e.g., Once, Every 5 minutes, Every 15 minutes).
For margin alerts, Once is usually sufficient. You don't want your desktop flooded with notifications every 5 minutes while you are trying to manage the position.
Ensure the TWS Alert checkbox is enabled so it pops up on your screen.
If you want email or SMS notifications, ensure your contact preferences are updated in Account Management on the web portal. (TWS alerts only work while TWS is open and running).

Step 5: Save and Test

Click OK to save your settings.
To test it, you can temporarily lower the percentage to 1% in a paper trading account, trigger a margin breach, and verify the alert pops up.

How to Set Up Margin Cushion Alerts on IBKR Mobile

Most traders don't sit at their TWS desk 24/7. The mobile app is where you manage risk when you are away from your terminal. Fortunately, IBKR has streamlined the alert setup on mobile.

Open the IBKR Mobile app (iOS or Android).
Tap the Menu icon (three horizontal lines) in the top-left corner.
Select Settings.

Step 2: Navigate to Notifications

In the Settings menu, look for Notifications or Alerts.
Tap on Account Alerts.

Step 3: Enable Margin Cushion

Find the Margin Cushion toggle and switch it ON.
Tap the percentage field next to it.
Input the same percentage you used in TWS (e.g., 20%). Consistency across platforms is key so you don't get confused about which threshold is active.

Step 4: Verify Push Notification Permissions

Go back to the main Settings menu.
Ensure Push Notifications are enabled for the IBKR app.
On iOS, go to your phone's Settings > IBKR > Notifications and ensure "Allow Notifications" is on, and "Sounds" and "Banners" are enabled.

The Hidden Danger: What the Margin Cushion Alert Does NOT Tell You

The margin cushion alert is a fantastic tool, but it is not a magic shield. There are three major blind spots you must be aware of in 2026.

1. The "Margin Rate" Shock

IBKR periodically adjusts its margin rates. If you are holding a large leveraged position and IBKR raises the margin rate for your account tier, your margin requirement suddenly increases.

Your margin cushion will shrink instantly. If the rate hike is large enough, it could trigger a margin call *without* the underlying stock price moving at all. The margin cushion alert will fire, but it will be too late to prevent the margin call.

Mitigation: Always monitor the IBKR Margin Rates page (archived) before holding large positions over weekends.

2. The "Haircut" Adjustment

IBKR applies haircuts (discounts) to certain securities, especially volatile stocks, options, and crypto assets. If a stock becomes more volatile, IBKR may increase the haircut on that specific position.

Again, your margin requirement spikes, and your cushion evaporates. This is common during earnings season. If you hold a volatile tech stock ahead of earnings, your 20% cushion might drop to 5% overnight.

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3. The "Alert Fatigue" Problem

If you set your margin cushion alert to 50%, you will get alerted constantly. Over time, you will start ignoring the notifications. This is dangerous.

When a real crisis hits, your brain will auto-dismiss the alert.

Best Practice: Treat margin alerts like fire alarms. You want them to be rare. If you are getting margin cushion alerts more than once a week, your threshold is too low, or your position sizing is too large.

Advanced: Automating Your Margin Defense with TWS

If you are an active trader on TWS, waiting for an alert and then manually clicking to reduce your position is too slow. You can set up an automated defense.

While TWS doesn't have a native "auto-liquidate at margin cushion X%" button, you can use Bracket Orders and Trailing Stop Losses to achieve a similar effect.

When you enter a long position, immediately set a trailing stop loss.
Set the stop loss at a distance that ensures you exit the trade *before* your margin cushion hits your alert threshold.

For example, if you buy 100 shares of a $100 stock on 2:1 margin, your initial margin cushion is roughly 50%. If your margin cushion alert is set to 20%, you need to calculate the price at which your cushion drops to 20%.

Using the formula: Margin Cushion = (Net Liquidation Value - Margin Requirement) / Net Liquidation Value, a 20% cushion means your Margin Requirement is 80% of your Net Liquidation Value.

Let's trace the math accurately. You buy 100 shares at $100 (Total Value = $10,000). You use 50% initial margin, meaning your Margin Requirement is $5,000. Your initial cushion is ($10,000 - $5,000) / $10,000 = 50%.

If the stock drops to $80, your Net Liquidation Value (NLV) is $8,000. Your Margin Requirement remains $5,000. Your cushion is now ($8,000 - $5,000) / $8,000 = 37.5%.

If the stock drops to $62.50, your NLV is $6,250. Your Margin Requirement is still $5,000. Your cushion is ($6,250 - $5,000) / $6,250 = 20%.

This means if your alert is set to 20%, the stock must drop to $62.50 to trigger it. To be safe, if your alert is set to 20%, calculate the price at which your cushion drops to 20%. If that price is $62.50, set your stop loss at $63.

By the time the stock hits $63, your stop loss executes, and you exit the trade. The margin cushion alert never even fires. This is the gold standard of risk management.

You can read more about setting up bracket orders in our guide on IBKR Bracket Orders and Stop Losses.

Troubleshooting: Why Isn't My Margin Cushion Alert Working?

If you've set up the alert but haven't received it when your margin cushion drops, check these common issues:

TWS is Closed: TWS alerts only work when TWS is open and connected to the server. If you close TWS at night, you will miss alerts. Use the mobile app as a backup.
Wrong Account: If you have multiple IBKR accounts (e.g., a cash account and a margin account), ensure you are configuring the alert on the correct account tab in TWS.
Notification Settings: On mobile, check that your phone's operating system isn't silencing the IBKR app. On TWS, check that the "Alerts" window isn't minimized or hidden behind other windows.
Paper Trading vs. Live: If you are testing in Paper Trading, ensure the Paper Trading account has enough virtual equity to actually trigger margin calculations. Sometimes, paper accounts have infinite buying power depending on the settings, which disables margin alerts.

FAQ

What is the default margin cushion percentage in IBKR?

Interactive Brokers does not set a default margin cushion percentage. The field is blank by default, meaning no alert is active until you manually check the box and input a percentage.

Does the margin cushion alert work for crypto trading on IBKR?

Yes. If you are trading crypto on margin (or using crypto as collateral for other margin positions), the margin cushion alert applies to your overall account margin requirement, which includes crypto haircuts. However, crypto haircuts are much larger than stock haircuts, so your cushion will drain much faster.

Can I set different margin cushion alerts for different accounts?

Yes. In TWS, you can switch between your accounts using the account dropdown menu. You must configure the margin cushion alert separately for each account.

Is the margin cushion alert free?

Yes. The margin cushion alert is a free feature built into both TWS and the IBKR Mobile app. There are no additional fees for setting up account alerts.

Can I get a margin call if my margin cushion alert hasn't triggered?

Yes. If you have a sudden, massive gap down in a stock (e.g., a -50% drop overnight), the market may open below your margin requirement. The margin cushion alert only triggers when the cushion *drops below* your threshold. If the market gaps below the threshold entirely, the alert might not fire before the margin call is issued. This is why stop losses are essential.

Risk Warning

Risk Warning: Crypto trading involves substantial risk of loss. Never invest more than you can afford to lose. This is not financial advice.

Conclusion

The margin cushion alert is one of the most underrated features in Interactive Brokers. It requires zero cost, takes two minutes to set up, and can save you from catastrophic liquidation.

Don't leave it to chance. Log into TWS and the IBKR Mobile app today, set your threshold to 20%, and sleep better at night. If you are looking to expand your risk management toolkit, check out our guide on IBKR Bracket Orders to automate your exits.