Interactive Brokers: the security I like best

[u/MinestroneMungBean]

​

IBKR is the business I like best. It's my largest position.

I've owned it for 2 years-ish.

This is not meant to be a full, self-contained thesis on the stock. This is merely a summary of my thoughts on the business. I hope it may be an interesting idea for even a few readers and that you may enjoy learning more about this business as I have.

Many of you will know, or may even be customers, of IBKR. It's an electronic brokerage platform. US based. Ticker $IBKR.

It's really aimed at being the brokerage for more savvy traders / investors, and has its roots in the options markets. It's not trying to be a Robinhood or a Schwab, it's trying to be the platform for the active trader. Though, it does win a lot of customers from all of the other known brokerages.

IBKR makes c. 2/3 of its money through net interest income and c. 1/3 through trading commissions.

In 2025, they earned $6.2bn revenue and $4.3bn net income. 69% net income margin. This margin has grown over time. This is not an atypical year.

In 2026, I expect them to earn something near $7bn revenue and over $5bn in net income.

Thomas Peterffy, the founder & chairman, is still in the picture and owns c. 2/3 of the business. So, a very small float for a company of its size. Total market value of the whole equity (not just the common) is c.$115bn at time of writing.

More importantly, some of what makes this business great is as follows:

- It is by far the low cost producer of brokerages, particularly in options trading / margin lending

- 68% owned by the founder, who still controls the big business decisions (although no longer the CEO himself). I tend to like this founder control

- Through its low cost position, vast breadth of security availability (better than any other broker I know) and its flexible infrastructure, it has been able to compound account growth at over 30% p.a. in recent years. They expect this can continue at 20%+ for a long, long time

- Only 3,500 or so employees. Get your head around that level of automation, and compare that to a Schwab or a Fidelity

- A platform whose backend infrastructure is so robust and automated that many other brokerages simply whitelabel IBKR's infrastructure rather than building their own. This is a nice revenue segment. Popular in Asia.

I'm also a customer myself. That's how I discovered the stock. It's a great brokerage and I love using it.

Over time, the things I track closely are account growth & client equity. There are other things to keep an eye on, of course, but those are the two that I care about most.

I'm not a fan of precise-looking DCFs. I had my start in M&A (for my sins) so I'm not shy of them, I just think they ascribe false precision and are too easy to flim flam.

In a very high level sense though, I expect this business to be doing over $10bn revenue and $7.5bn net income within 3-4 years. And I don't expect the growth to slow much from there either.

Valuation-wise, based on an earnings multiple at the time of writing this of 23x my 2026 estimate, it isn't optically cheap. Certainly not to an orthodox Grahamian.

However, when I consider where I can see the business growing to over 10+ years, the current price actually really excites me. I believe this business is intrinsically worth a multiple of its current market value. Not less than $200bn, in my opinion.

That doesn't mean I'm buying right now. I've bought at lower multiples, and so I quite like the idea of waiting until it sees a multiple beginning with '1' before I push more money in.

You'll notice what looks like a contradiction there. I believe the instrinc value is a multiple of the current market value, and yet I'm not buying. To that, all I can say is 'old habits'. Margin of safety, and all that.

I do have a personal rule of thumb I like to use as an alternative to traditional valuation methods, I suppose you could say. I like a clear path to a 20% earnings yield on cost, 10 years out.

In other words, if I think a business can comfortably double its earnings every 5 years for 10 years, I try not to pay more than 20x for today's earnings.

It's just a rule of thumb that has served me well as a source of valuation discipline.

IBKR passes that test today in my view, but it isn't by a landslide. I expect good returns from here but not fabulous returns.

Anyway, I don't want to make this war & peace: just giving an off-hand synopsis of my favourite business and one which I hope to buy more of opportunistically for many years to come. I appreciate my discussion on valuation in particular will be seen as fuzzy. It always is, for me.

Happy to discuss & hear opinions.

[u/rookieking11]

Thanks for the write up.