From one quarter to the next, the group created and headed by the excellent Thomas Peterffy recorded a very sharp rise in trading fees and commissions (+36%) and net interest margin (+9%).

This performance is all the more remarkable given that the third quarter is generally the least active of the year on the financial markets. Unsurprisingly, Interactive Brokers, as vigilant as ever in controlling its costs, maintains a pre-tax margin firmly anchored above 70%.

Over the past five years, Interactive Brokers has undergone an extraordinary expansion sequence. The number of customer accounts it administers has quadrupled over this period, representing an annual growth rate in excess of 37%.

This commercial momentum, coupled with rising interest rates, should boost net interest margin to $3 billion this year, i.e. three times more than in 2019, while income from fees and commissions is up 50% over the period, reaching $1.5 billion in 2024, compared with $1 billion at the end of 2019.

On the other hand, operating expenses are rising at a slower pace, hence the clear expansion of margins in the meantime. We would expect no less from a group whose entire strategy is built around the ongoing automation of its systems; this DNA makes it a natural and privileged candidate for economies of scale.

Interactive Brokers is a situation "à la Peter Lynch", to quote the former Fidelity star and author of excellent popular stock-market books, and to reiterate his theory that shareholders often have an intellectual as well as a lucrative interest in investing in companies whose services they particularly appreciate.

A satisfied Interactive Brokers customer would have been well advised to acquire shares in his favorite broker, since in ten years, his profit per share had increased sixfold; indeed, his share price had followed this very trajectory. 

Over the entire period, valuation remained anchored in a well-defined range between twenty and twenty-five times earnings. Each move below this threshold represented an additional opportunity to accumulate. In this respect, there's no reason why the future should differ from the past.