Following a year in which the S&P 500 rose 16% and the Nasdaq Composite jumped 20%, many growth stocks now look overpriced. But if you look close enough, there are a few growth stocks that still look attractive even after last year's big gains. Online broker Interactive Brokers (IBKR 2.15%), which boasts a low-cost and highly automated operation, arguably stands out as one of the few fast-growing companies that still look attractive.
In fact, the company's stock even outperformed Nvidia last year as it aggressively took market share from competitors. Yet I believe shares are still attractive -- even after such a massive run-up. This is Interactive Brokers' strong stock performance has been supported by extraordinary underlying business momentum.
Here's why Interactive Brokers stands out as a top growth stock to buy for 2026 and beyond.
Image source: Getty Images.
A broker built for scale
Interactive Brokers is an online brokerage that lets individuals and institutions trade across many markets. And behind this model is extreme automation. The company's culture of automation overflows into every area of its business, from administrative and compliance tasks to client onboarding. Its high degree of automation ultimately helps Interactive Brokers differentiate itself with a low-cost value proposition for its customers.
Its highly automated and efficient business model also helps it expand internationally and serve more markets than most brokers. At Interactive Brokers, clients from more than 200 countries and territories can invest in over 170 global markets.
The company's third-quarter results showed how powerful this scaled and streamlined operating model can be. Interactive Brokers reported third-quarter revenue of $1.655 billion in Q3 2025, up 21% year over year from $1.365 billion a year earlier. And earnings per share rose 40% to $0.59. Fueling this growth was commission revenue of $527 million, up from $421 million in the year-ago quarter, and net interest income of $967 million, up from $736 million.
The metrics that matter the most
Of course, the most important figures in Interactive Brokers' third-quarter update were the drivers behind its financial growth. The company continues to add customers at a strong pace, and those customers are bringing more assets onto the platform.
In Q3, Interactive Brokers customer accounts grew 32% year over year to 4.13 million. Further, customer equity rose 40% year over year to $357.5 billion. And its customers remain engaged. Daily average revenue trades (DARTs), or the average number of trades per day during the quarter that generated revenue, increased 34% year over year to $3.62 million.
Importantly, we also have more recent data on the business. Interactive Brokers provides monthly updates on its key brokerage metrics. Unsurprisingly, momentum has continued since the quarter ended. In its December 2025 brokerage metrics update, Interactive Brokers reported total client accounts of about 4.4 million, up 32% year over year. It also reported client equity of $779.9 billion, up 37% year over year.
Notably, however, there was one meaningful slowdown in December compared to Interactive Brokers' Q3 update: DARTs growth slowed significantly. DARTs in December were about 3.384 million, up 4% year over year. Of course, it's normal to see lumpiness in this metric. Further, given the company's continued strong customer account growth during December, it's not necessary for Interactive Brokers to always grow DARTs; customer account and client equity growth continue to do the heavy lifting even when DARTs growth slows.
Time to buy Interactive Brokers stock?
With the stock rising about 62% over the past 12 months as of this writing, investors might think that shares should be avoided. Sure, I do think there is more valuation risk baked into the price today than there was a year ago. But this doesn't mean shares aren't attractive for investors with a long time horizon. With a price-to-earnings ratio of 34 and a forward price-to-earnings ratio of 29, the stock isn't cheap. However, given how the company's powerful and easily scalable business model is translating into rapid customer growth, I think that the stock is worth its current valuation.
With this said, Interactive Brokers is a high-risk stock for investors with extremely high risk tolerances. As an online broker, the company's business can pick up momentum during periods in which equities and trading are viewed favorably and can take a hit during periods of market pessimism. Given how strong the market has performed over the past year, we're clearly in a period of optimism. An environment like this benefits Interactive Brokers. But if the market falls and investors become more pessimistic, stocks could fall substantially, and client equity at Interactive Brokers can take a hit; in turn, customer growth could slow, and customer activity could plummet.
Given these risks, even though I believe shares are attractive for investors willing to hold for the long haul, it would likely be wise to keep the position small.
