Interactive Brokers 10-Qquarter ended 2026-09-30

Executive Summary

Interactive Brokers provides automated trading, custody and lending services to brokerage customers worldwide, earning commissions, fees and interest on customer financing and cash. It is concentrating on expanding its global customer base while using automation to keep staffing growth modest. Q3 revenue grew 16%, but growth slowed from the nine-month pace as trading activity cooled and lower interest margins partly offset expanding customer balances. The opportunity is to turn rapid account growth into sustained trading and lending income; the principal threats are weaker activity, lower rates and losses if customer collateral cannot be liquidated during market stress.

What's Happening in the Business

Customer expansion continued: accounts reached 5.58M, up 35% Y/Y. The platform serves clients in more than 200 countries and territories, connecting them to more than 175 exchanges and market centers. Customer daily average revenue trades rose 18% Y/Y, but fell 11% from Q2; their nine-month growth was 26%. The customer base is expanding faster than current trading activity.

Lending and customer cash were stronger growth engines. Average margin loans increased 47% to $104B, while average customer credit balances rose 25% to $177B. Those larger balances outweighed lower yields, although Q3 net interest margin fell to 1.99% from 2.16%.

Automation continues to support scale. Average Q3 headcount rose 5% to 3,274, substantially slower than accounts. Investment supports technology capacity, cybersecurity and regulatory needs, rather than a disclosed major acquisition or change in business model.

Key Financial Highlights

Q3 and 9M figures cover periods ended 9/30/2026; changes are Y/Y.

• Interest contribution: Net interest income supplied $187M of the $259M quarterly revenue increase; balance growth, rather than stronger lending yields, drove the gain.
• Trading monetization: Commission per cleared commissionable order fell 4.1% to $2.59 because orders were smaller, explaining why commissions lagged trading growth. Futures contracts increased 13%, while options contracts declined 1% and stock shares declined 24%.
• Costs and margins: Q3 execution, clearing and distribution expense rose 46% to $134M, including $26.0M of additional regulatory fees passed through to customers. Pretax margin eased to 78% from 79%; nine-month margin improved to 77% from 76%.
• Geographic contribution: International revenue rose 35% to $633M, supplying $164M of quarterly growth, versus U.S. growth of 8.0%. These figures identify where subsidiaries book transactions, not customer location.
• Capital protection: Regulated subsidiaries held $18.0B of capital against $3.33B of requirements. This cushions losses, but regulatory and customer-segregation rules limit how freely funds can be distributed.

Risk Assessment

• Customer credit and liquidation: The enlarged margin-loan book exposes IBKR to collateral shortfalls during abrupt or illiquid markets, when automated liquidation may fail; clearing indemnities can create additional, unquantifiable obligations.
• Rates and trading activity: Interest income dominates revenue, while commissions depend on customer activity, so falling benchmark rates or a further trading slowdown could overwhelm customer growth.
• Platform reliability and cybersecurity: Execution, real-time margin monitoring and liquidation depend on automated systems; outages or attacks could disrupt service and weaken credit controls simultaneously.
• Currency exposure: About 24% of equity is denominated in non-U.S.-dollar currencies and generally is not hedged back to dollars, creating volatility across earnings and other comprehensive income.

This 10-Q lists no risk factors of its own and refers to the annual report. The risks above come from the rest of this filing. Full list: FY2025 10-K.

What to Watch

• Account conversion: Accounts grew 35%, faster than trading and commissions; future filings should show whether newer customers become active users or leave growth concentrated in low-activity accounts.
• Lending economics: Average margin loans reached $104B while net interest margin compressed; sustained balance growth with stable credit outcomes would support earnings, whereas weaker balances or credit losses would undermine that engine.
• Automation at scale: Headcount is growing much slower than accounts; stable service and margins would validate the model, while outages or sharply higher support and compliance spending would challenge it.