Interactive Brokers is an automated global broker. It makes money in two main ways. First, it charges customers a small fee every time they place a trade, whether that trade is in stocks, options, futures, currencies, bonds, or cryptocurrencies. Second, it earns interest income: when customers borrow money to trade (called a margin loan), Interactive Brokers charges them interest, and it also earns interest by investing the large piles of cash customers keep parked in their accounts. Those two streams, commissions from trades and interest from cash and loans, together produced $6.205 billion in total net revenues in 2025. The diagram below traces where the money goes.
How Interactive Brokers Makes Money
flowchart LR
A["Customer Accounts
4.4M accounts"] --> B["Assets Under
Custody
779.9B USD"]
B --> C["Trade Execution
& Order Routing"]
C --> D["Commission &
Execution Revenue"]
B --> E["Cash Balances
& Securities
Lending"]
E --> F["Interest & Lending
Fees Revenue"]
D --> G["Total Revenue
6.2B USD"]
F --> G
G --> H["Proprietary Tech
& Platform Ops"]
H --> I["Low Cost
Structure"]
I --> J["Customer
Acquisition &
Retention"]
J --> A
H --> A
Five years of financials tell a clear story of acceleration. Revenue grew from $2.7 billion in 2021 to $6.2 billion in 2025. That is more than a doubling in four years. The customer base grew just as fast, from around 2.6 million accounts in 2023 to 4.4 million by the end of 2025. The money those customers hold on the platform, called customer equity, rose from $426 billion in 2023 to $779.9 billion in 2025. More customers bring more cash, more cash earns more interest, and more active traders generate more commissions. Each part feeds the others.
Total Net Revenue (2021 to 2025)
Total net revenues in billions of dollars. Source: company filings.
What makes the financial picture particularly striking is not just the revenue growth but the efficiency behind it. In 2025, Interactive Brokers kept its total non-interest expenses at just 23% of net revenues. That means for every dollar the company brought in, it kept 77 cents as pre-tax income. That pretax profit margin rose from 71% in both 2023 and 2024. The company runs on largely automated systems, which means it can handle far more customers and trades without hiring many more people. It had 3,182 employees at the end of 2025 serving 4.4 million accounts.
77%
Pretax profit margin in 2025, up from 71% in the prior two years
The interest income side of the business does carry a warning. When interest rates fall, the company earns less on the cash its customers hold and on margin loans. In 2025, the U.S. Federal Reserve cut its benchmark rate three times, and the net interest margin (the percentage the company earns on its interest-bearing assets after paying interest out to customers) dropped from 2.35% in 2024 to 2.08% in 2025. Net interest income still grew by 13% because customer balances grew so much, but if rates keep falling while customer growth slows, those two forces could stop offsetting each other.
What is a margin loan?
When a customer wants to trade with more money than they actually have in their account, they can borrow the difference from their broker. That borrowed amount is called a margin loan. The broker charges interest on it, just like a bank charges interest on a personal loan. Interactive Brokers had average margin loan balances of $69.978 billion in 2025, making this a very large source of interest income.
The company has real compliance and technology risks on its record. Between 2016 and 2021, it accidentally allowed more than 200 people from countries under U.S. sanctions, including Iran and Cuba, to make over 12,000 trades. In 2025, Interactive Brokers paid an $11.8 million settlement for those violations. In 2020, when oil prices went negative for the first time ever, its systems were not prepared, leading to a $1.75 million fine and $82.57 million in refunds to affected customers. In 2024, a technical glitch in New York Stock Exchange systems caused the price of Berkshire Hathaway stock to crash briefly, and Interactive Brokers absorbed a $48 million loss covering customer positions. These are not isolated incidents.
$48M
Loss absorbed by Interactive Brokers in 2024 after a stock price glitch at the New York Stock Exchange
What does it mean to be a clearing member?
When a trade happens, someone has to guarantee it gets settled properly, even if one side of the trade fails. Interactive Brokers acts as a clearing member for most of its customers, meaning it stands behind their trades. If a customer cannot pay back a margin loan or a trade goes wrong, Interactive Brokers absorbs that loss first. This is why technology failures and customer defaults are particularly costly for the company.
Beyond technology failures, the company is regulated by multiple agencies across many countries, including the SEC, FINRA, and the CFTC in the United States, and regulators in Canada, the United Kingdom, Ireland, Switzerland, Hong Kong, Singapore, Japan, India, and Australia. Any one of those regulators can restrict how the company operates, impose fines, or require expensive changes to its systems. The company has paid tens of millions of dollars in regulatory penalties between 2018 and 2025 for failures in monitoring suspicious activity and recording employee communications. That pattern of fines across multiple years suggests the compliance challenge is structural, not accidental.
2025
milestone
Added to the S&P 500 Index
On August 28, 2025, Interactive Brokers was added to the S&P 500 Index. Inclusion in the S&P 500 typically triggers automatic purchases by index funds and exchange-traded funds that track the index, broadening the shareholder base. The company cited this as recognition of its financial performance, sustained profitability, and position as a leading global automated brokerage platform.
The growth in trading volumes is the most important operational trend to watch. In 2025, total customer orders executed reached 915.6 million, up 38% from 2024. Options contracts traded by customers rose 26%, futures rose 12%, and stock share volumes rose 38%. Daily average revenue trades (the number of trades each day that generate revenue) rose 40% to 3.685 million. These are large jumps. The question is whether they reflect a permanent shift in how many people trade actively, or whether they were driven by unusually high market volatility and enthusiasm that may not repeat.
2.562 million
Customer accounts in 2023
4.399 million
Customer accounts in 2025
Account growth of 72% in two years, driven by global expansion and new product offerings.
Interactive Brokers earns a 0.50 percentage point spread on customer cash balances when the U.S. federal funds rate is above 0.50%. That spread has been in place since May 2022. If rates fall back toward zero, that guaranteed floor disappears along with a meaningful slice of interest income.
The Bet
Interactive Brokers keeps attracting new, active customers at a pace fast enough to offset two headwinds: falling interest rates that shrink what the company earns on each dollar of customer cash, and a per-trade commission that has been drifting lower (average commission per cleared commissionable order fell from $2.86 in 2024 to $2.68 in 2025). If customer growth slows while rates continue to decline, both of the company's major revenue streams compress at the same time. The automation advantage that drives the 77% pretax margin only holds its value if volume keeps growing to spread the fixed technology costs across more and more trades.
Open question
Interactive Brokers has built a genuinely efficient machine. It serves 4.4 million accounts with 3,182 employees, earns a 77% pretax margin, and has grown revenue more than twofold in four years. But nearly 57% of its 2025 net revenues came from interest income, a figure that is sensitive to central bank policy decisions the company cannot control. Commission revenue is growing fast but the average fee per trade is shrinking. And a track record of technology failures and compliance penalties across multiple years raises a real question about whether the automation that drives profits is being maintained and updated as fast as the business is growing. Can Interactive Brokers sustain its revenue trajectory if interest rates fall further, or does the model require both a large and growing customer base AND a high-rate environment to deliver the margins investors have come to expect?
Compiled · 10-K · FY2025
Regulatory
The company operates through subsidiaries regulated by multiple agencies including the SEC, FINRA, CFTC, and foreign regulators in Canada, UK, Ireland, Switzerland, Hong Kong, Singapore, Japan, India, and Australia. Changes to regulations or enforcement actions by any of these bodies could restrict the company's ability to operate, require expensive compliance upgrades, or result in fines and penalties that materially harm profitability.
Technology and Operations
The company's market-making and trading activities depend on proprietary pricing software that evaluates and rebalances positions many times per second. If this software has flaws or failures, it could generate unexpected unprofitable trades resulting in material losses. The company does not have fully redundant backup systems for all critical functions.
Financial
As a clearing member firm, the company is ultimately responsible for customer defaults on margin loans and securities transactions. If customers cannot repay or maintain adequate collateral, the company absorbs losses. Additionally, if other clearing members default, the company may be required to pay pro rata assessments from its own funds.
Business Model
The company's revenues depend heavily on trading volume and interest rate levels, both beyond its control. Market downturns, reduced trading activity, or changed interest rates can cause significant revenue and profit swings. The company also faces intense competition from brokers with greater resources and from zero-commission competitors.
Cryptocurrency
The company relies on third-party cryptocurrency service providers to offer custody and trading services. A data breach at one of these providers could result in irreversible customer losses. Additionally, changing cryptocurrency laws and regulations could prevent the company from offering these services in the future.
10-K Item 1A · Risk Factors
