Interactive Brokers Client Equity Jumps 27% to $964.7…

Interactive Brokers closed September with 5.576 million client accounts and $964.7 billion in client equity, a 27% year-over-year increase in assets, according to its monthly operating metrics. The account base expanded 35% from a year earlier and 2% from August, with roughly 116,000 accounts added during the month, taking the total from 5.460 million.

Trading activity trails account growth

Daily Average Revenue Trades reached 4.111 million, up 6% year over year but 4% below August. On a per-account basis, annualized average cleared DARTs eased to 159 from 168 a month earlier. Client equity also barely moved from August's $962.8 billion, so assets did not grow in step with the customer base. New accounts typically take time to fund and become active, and monthly DARTs are shaped by volatility and the number of trading days. Earlier in the year the alignment was tighter: April client equity rose 48% year over year, DARTs 11% and accounts 31%.

Margin balances carry the revenue signal

Client margin loans climbed to $105.2 billion from $101.5 billion in August, up 36% annually and ahead of both the 27% rise in client equity and the 20% growth in client credit balances, which reached $186.2 billion. Margin loans equated to roughly 10.9% of client equity at September's end, versus about 10.5% in August. Interest income matters to the revenue mix: first-quarter net interest income rose 17% to $904 million, aided partly by higher average customer margin loans and credit balances.

The average commission was $2.57 per cleared commissionable order, including exchange, clearing and regulatory charges. Stock orders averaged $1.94 on 656 shares, equity options $3.67 on 6.2 contracts and futures $4.36 on 3.1 contracts. For IBKR Pro customers trading U.S. Reg NMS stocks, the all-in cost of execution and clearing was about 1.2 basis points of trade value against the daily VWAP benchmark, down from 2.1 basis points in August, while the rolling 12-month average held at 2.5 basis points.

The broker has also widened its product range, including a unified prediction-market interface spanning Kalshi, CME Group and ForecastEx. Third-quarter earnings on Oct. 15 should show how softer sequential trading activity and heavier margin borrowing translated into commissions and net interest income.