Interactive Brokers’ margin loans grow 49% to $100.7B as investors pile into leverage

Interactive Brokers just crossed a milestone that says a lot about where investor sentiment sits right now. Client margin loan balances reached $100.7 billion in July 2026, up 49% from the same period a year earlier. When your customers are borrowing that aggressively to place bets, either the market is very confident or very reckless. Possibly both. The numbers behind the leverage boom The $100.7 billion figure is actually the more conservative way to frame it. Average client margin loans during Q2 2026 came in at $108.5 billion, representing a 67% year-over-year increase. That’s the kind of growth rate that would make a SaaS startup jealous, except this isn’t recurring software revenue. It’s borrowed money. The lending surge has been a direct boon to IBKR’s bottom line. Net interest income rose 23% in Q2 2026, largely driven by the expanded margin book. Think of it as a bank that doesn’t have to chase depositors because its customers keep voluntarily signing up for loans. Client credit balances, essentially cash sitting in brokerage accounts, climbed to $180.5 billion, a 25% increase year-over-year. Total client assets reached $907 billion during the same period, even as trading ...