A global trading machine with rate risk
- IBKR makes money mainly from trade commissions and net interest income on customer cash and margin loans.
- Commission revenue rose 27% in 2025 as customer activity jumped across stocks, options, and futures.
- Net interest income rose 13% in 2025, but net interest margin fell to 2.08% as global rates moved lower.
- About 84% of customers live outside the U.S., which makes IBKR more global than many U.S. brokers.
- The business scores well on performance and financial health, but valuation looks tight if growth cools.
Volume is winning, rates are biting
The bull case is simple: IBKR is built for active traders and institutions that want low-cost access to many markets. In 2025, commission revenue rose 27% as stock volume rose 38%, options volume rose 26%, and futures volume rose 12%. That kind of activity helps an automated broker because more trades can run through the same platform.
The second engine is interest income. IBKR earns money from customer cash, margin loans, and securities lending. Net interest income rose 13% in 2025 to $3,563 million because average customer balances and margin loans were higher.
The bear case is also clear. Net interest margin, which is the spread IBKR earns on interest assets after funding costs, fell from 2.35% to 2.08% in 2025. The filing says lower global interest rates were the main cause. If central banks keep cutting, balance growth may not fully protect earnings.
Finn's view is balanced. IBKR is a strong operator with global reach, but the stock has to justify a lot of future growth. The key question is whether high trading activity and customer balance growth can keep offsetting lower interest spreads.
A broker that earns on trades and cash
IBKR is an automated electronic broker. It routes, executes, clears, and services trades for individual investors, hedge funds, financial advisors, proprietary trading groups, introducing brokers, ETFs, and other institutions.
The company has two main money streams. First, it earns commissions when customers trade. Second, it earns net interest income from customer credit balances, margin loans, and related securities lending activity.
Scale matters here. IBKR connects customers to more than 160 electronic exchanges in 36 countries. More accounts and more trades can add revenue without needing a branch network like an old-style broker.
Where it can break is in the spread. If rates fall, the interest earned on customer cash and loans can shrink. If trading volume fades at the same time, both engines can slow together.
Many markets, one account
Stocks and ETFs
Stocks and ETFs are core products for both retail and institutional clients. Equity volume rose 38% in 2025, giving commissions a major lift.
Options
Options are a major activity driver for active traders. Options volume rose 26% in 2025, after strong growth through 2025 quarters.
Futures and forex
Futures and foreign exchange broaden the platform for global and professional users. Futures volume rose 12% in 2025, though earlier 2025 filings showed some quarter-to-quarter pressure in futures and forex.
Margin lending and customer cash
Margin loans and customer credit balances feed net interest income. This engine grew in 2025, but its margin fell when global rates declined.
Bonds, mutual funds, and precious metals
These products make the account more useful beyond fast trading. They help IBKR serve advisors and institutions that need broad asset access.
Crypto and forecast contracts
Crypto and ForecastEx event contracts are newer parts of the offer. ForecastEx may open a new market, but the company says prediction market rules are uncertain and still changing.
Mostly outside the U.S.
This mix uses the latest disclosed customer residence data in the internal thesis and 2026 Q1 filing trail: about 84% of customers live outside the U.S. This is a customer mix, not a revenue mix, and institutional accounts hold over half of customer equity.
What could go wrong
Lower rates squeeze interest spreads
High impact · Medium oddsNet interest margin fell from 2.35% to 2.08% in 2025, mainly because global rates moved lower. Net interest income still grew 13%, but that was helped by higher customer balances and margin loans. If rates fall faster than balances grow, earnings could slow.
Trading activity cools
High impact · Medium oddsIBKR benefited from heavy customer trading in 2025, with commission revenue up 27%. That can reverse if markets get quiet or customers trade less. Q2 2025 also showed average commission per commissionable order fell 12% to $2.65, so mix and order size matter too.
ForecastEx faces tighter rules
Medium impact · Medium oddsIBKR began offering forecast contracts through ForecastEx, a CFTC-registered exchange and clearinghouse. The 2025 Form 10-K says the legal and regulatory framework for prediction markets is uncertain and continues to evolve. New limits could reduce listings or slow this growth option.
Cyber or data privacy breach
High impact · Medium oddsIBKR holds sensitive account, trading, and personal data for customers in more than 200 countries and territories. A breach could hurt trust, trigger fines, and raise spending on security. The risk is larger because the platform is global and highly automated.
Global compliance gets harder
Medium impact · Medium oddsAbout 84% of customers live outside the U.S. That gives IBKR a long growth runway, but it also means many regulators, market rules, tax regimes, and sanctions lists. A change in one large region could slow new accounts or raise costs.
In one breath
How does Interactive Brokers make money?
IBKR mainly earns commissions when customers trade and net interest income from customer cash, margin loans, and securities lending. It also earns from serving many customer types, including individuals, advisors, hedge funds, and trading firms.
Why do interest rates matter so much for IBKR?
IBKR earns a spread on customer balances and margin loans. When benchmark rates fall, that spread can shrink, which is why net interest margin fell to 2.08% in 2025.
Is Interactive Brokers mostly a U.S. broker?
No. About 84% of its customers live outside the U.S. in more than 200 countries and territories, and its platform connects to more than 160 electronic exchanges in 36 countries.
What is ForecastEx?
ForecastEx is IBKR's CFTC-registered exchange and clearinghouse for event-based forecast contracts. It could add a new product line, but the company says prediction market rules are uncertain and still changing.