Mental shortcuts are helpful, and one framework I use involves stocks that have the potential to double in value. I'm looking for stocks that can double in five years. At that rate, a stock would go up about 15% annually, which would be higher than the average of the S&P 500.
I'd like to explain why energy drink maker Celsius Holdings (NASDAQ: CELH) and language-learning company Duolingo (NASDAQ: DUOL) are two stocks that have the potential to double in value over the next five years. For investors who have $2,000 to put to work, I believe either one would make a good investment.
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Celsius stock
Sales for Celsius' line of energy drinks have grown significantly in recent years. Its organic growth cooled in 2025. But two acquisitions this year -- Alani Nu and Rockstar Energy -- carried the company to astounding 173% net sales growth in the third quarter of 2025. There's good reason to believe it can continue.
For its namesake drink line, Celsius' growth in recent years was boosted by a strategic distribution deal with snack and beverage giant PepsiCo. As drinks entered PepsiCo's distribution network, growth soared. Now growth can jump again with Alani Nu's drinks entering PepsiCo's system.
To be clear, retail sales of Alani Nu more than doubled in Q3 compared to the same quarter of 2024, so growth is already red-hot. But Alani Nu only entered PepsiCo's distribution system on Dec. 1, which was after the quarter ended. With the new distribution, PepsiCo can now reach more places with Alani Nu, potentially boosting growth for Celsius.
Celsius has also made moves to boost profitability, such as acquiring its manufacturer, Big Beverages.
Herein lies my investment thesis in a nutshell: I believe that Celsius can double its revenue over the next five years, driven by the contribution of new brands and growth in its nascent international operations. Additionally, I believe the company can grow its profits faster than revenues, thanks to good management.
If those two things happen, I believe Celsius stock would likely double in value over the next five years, which is why it could be a worthwhile investment today.
Duolingo stock
Duolingo is a revenue growth machine and a free cash flow machine, and that's why I can't ignore this stock. According to data from Pacer Advisors, the best S&P 500 stocks to own over five-year and 10-year periods are in the top quartile for both growth and free-cash-flow margins. The worst performers over that time are the high-growth, low-margin businesses.
In Q3 2025, Duolingo's revenue increased 41% year over year to $272 million, ranking it among the fastest-growing companies. But the company also had a free-cash-flow margin of nearly 29%, which few companies can match.
In short, if it can sustain anything like this, Duolingo stock will likely do very well, potentially doubling in the next five years.
I believe that Duolingo can sustain its growth. The company's gamified language-learning app seems to attract new users with ease -- it ended Q3 with 135 million monthly active users, up 20%. But it's also converting free users into paying subscribers. In Q3, 9% of its users were paying subscribers, tying its highest penetration rate so far.
Duolingo's simplest path to growth from here will be converting more users into subscribers. Since such a small percentage of users are paying subscribers today, I believe it's within the company's ability.
This is a digital business, meaning Duolingo can easily grow profits as revenue scales. Management does need to remain disciplined, yes. But this company has generated positive free cash flow every quarter for nearly six years. Therefore, I don't think investors should worry that management will suddenly lose its grip on the business.
Duolingo stock has dropped more than 60% from its high in 2025. It now trades at 26 times its free cash flow, which is a bargain for a company growing at such a rapid pace and with such high margins.
There are a lot of promising stocks out there. But few are growing as well as Duolingo and Celsius while also demonstrating some tantalizing profitability. That's why these two stocks are among my top picks right now.
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Jon Quast has positions in Celsius and Duolingo. The Motley Fool has positions in and recommends Celsius and Duolingo. The Motley Fool has a disclosure policy.