Up 52% in my ISA in 2025, this growth stock’s on fire! What’s going on?

This investor’s favourite new growth stock is off to a flying start this year, posting strong gains in his ISA portfolio in recent days.

| More on:

The content of this article was relevant at the time of publishing. Circumstances change continuously and caution should therefore be exercised when relying upon any content contained within this article.

You’re reading a free article with opinions that may differ from The Motley Fool’s Premium Investing Services. Become a Motley Fool member today to get instant access to our top analyst recommendations, in-depth research, investing resources, and more. Learn More.

Happy woman commuting on a train and checking her mobile phone while using headphones

Image source: Getty Images

I’ve been loudly banging the drum for Duolingo (NASDAQ: DUOL) all year long. And putting my money where my mouth is, I’ve bought this growth stock twice in my ISA since the start of 2025.

Recently, the Duolingo share price hit a 52-week high after surging 21.6% in one day (2 May). This took the year-to-date return to 52%.

Here’s why the stock’s been on fire, and why I think it will head even higher in the years ahead.

C’est magnifique!

Launched in 2012, Duolingo is the world’s leading language learning app, offering a ‘freemium’ model alongside two paid subscription tiers. Its mission is “to develop the best education in the world and make it universally available“.

The stock’s spike to a record high last week came after the firm released fantastic Q1 results. Revenue jumped 38% year on year to $231m, beating analysts’ estimates for $223m.

Daily active users surged 49% to 46.6m, as it added more daily users than ever. Monthly active users increased 33% to 130.2m, while paid subscribers rose 40% to 10.3m.

Adjusted EBITDA advanced 27% to $62.8m and free cash flow totalled $103m. Earnings per share (EPS) of $0.72 breezed past analyst expectations of $0.52.

Management raised its full-year revenue guidance to $987m-$996m, which would represent around 33% growth.

Theoretical risk becomes real

Now, the stock isn’t without risk. Back in December, I wrote: “One risk here is the emergence of an AI-powered competitor offering advanced features for free that Duolingo currently charges for.”

Lo and behold, it looks likely we have one in the shape of Google Translate. Various reports say that the tech giant is planning to launch an AI-powered practice mode. So this risk isn’t theoretical anymore.

That said, not everything Google touches turns to gold. Its attempt at a social media platform to compete with Facebook — called Google+ — never caught on. Meanwhile, its music streaming service — YouTube Music — hasn’t stopped Spotify’s impressive growth trajectory.

Nevertheless, it’s something I’ll be monitoring moving forward.

AI-powered growth

One thing I like about Duolingo is that it’s aggressively leaning into generative AI. Its Max subscription tier, which includes AI-powered conversation practice sessions, is attracting more learners to sign up.

And last week, the company launched 148 new language courses, doubling its offering overnight. For context, it took 12 years for mainly humans to create 100 courses, but just 12 months for AI to produce 148.  

Moreover, this significantly enhances the market opportunity for Asian users to learn popular European languages and vice-versa: 

Source: Duolingo.

Growing optionality

After its surge, the stock’s trading at around 22 times this year’s expected sales. That’s far from cheap, even if Duolingo beats this forecast.

However, its courses extend beyond languages to maths and music, while the firm’s about to launch a chess course. So the overall opportunity’s expanding.

Following the results, Morgan Stanley’s Nathan Feather said: “Duolingo’s unique, gamified approach to learning allows it to combine the mobile gaming and language learning markets for a $220bn total addressable market. With sub-1% share, it is heavily underpenetrated.

While I think the stock’s worth considering for long-term investors, the high valuation cannot be ignored. Therefore, it might be worth thinking about building out a full position on dips over time.

Ben McPoland has positions in Duolingo. The Motley Fool UK has recommended Duolingo. Views expressed on the companies mentioned in this article are those of the writer and therefore may differ from the official recommendations we make in our subscription services such as Share Advisor, Hidden Winners and Pro. Here at The Motley Fool we believe that considering a diverse range of insights makes us better investors.

More on Investing Articles

Man writing 'now' having crossed out 'later', 'tomorrow' and 'next week'
Investing Articles

The best time to buy stocks? It might be right now

Short-term issues that delay long-term trends create opportunities to buy stocks. And that could be happening right now with a…

Read more »

Queen Street, one of Cardiff's main shopping streets, busy with Saturday shoppers.
Investing Articles

Here’s why Next stock rose 5% and topped the FTSE 100 today

Next was the leading FTSE 100 stock today, rising 5%. Our writer takes a look at why and asks if…

Read more »

Renewable energies concept collage
Investing Articles

Up 458% in a year, could the Ceres Power share price go even higher?

Christopher Ruane reviews some highs and lows of the Ceres Power share price over the years and wonders whether the…

Read more »

Rolls-Royce's Pearl 10X engine series
Investing Articles

Are the glory days over for Rolls-Royce shares?

Rolls-Royce shares have soared in recent years. Lately, though, they have taken a tumble. Could there be worse still to…

Read more »

Group of friends meet up in a pub
Investing Articles

Are ‘66% off’ Diageo shares a once-in-a-decade opportunity?

Diageo shares have taken another hit in the early weeks of 2026. Are we looking at a massive bargain or…

Read more »

Investing Articles

Meet the UK stock under £1.50 smashing Rolls-Royce shares over the past year

While Rolls-Royce shares get all the attention, this under-the-radar trust has quietly made investors a fortune. But is it still…

Read more »

UK financial background: share prices and stock graph overlaid on an image of the Union Jack
Investing Articles

Down 19%, the red lights are flashing for Barclays shares!

Barclays shares have fallen almost a fifth in value as the Middle East war has intensified. Royston Wild argues that…

Read more »

Aviva logo on glass meeting room door
Investing Articles

After falling another 5%, are Aviva shares too cheap to ignore?

£10,000 invested in Aviva shares five years ago would have grown 50% by now. But what might the future hold,…

Read more »