3 No-Brainer Growth Stocks to Buy With $100 as 2026 Begins

Growth stock investors have had a great run over the last few years. The S&P 500 Growth Index is up over 112% since the start of 2023. That's more than double the returns of its counterpart, the S&P 500 Value Index.

But as we enter 2026, many fear growth stocks may be about to run out of steam. And while many stocks have climbed significantly faster than their underlying financial results, leaving their valuations stretched, there are still plenty of great growth stocks worth buying, even if you only have $100 to get started.

Here are three no-brainer growth stocks to buy right now if you have $100 available to invest.

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1. The Trade Desk

The Trade Desk (NASDAQ: TTD) faced a couple of big challenges in 2025.

First, its transition to its new artificial intelligence (AI)-powered ad-buying platform, Kokai, had some hiccups. Kokai was designed to offer marketers better bid decision tools with improved measurement and forecasting capabilities. While the replatforming was designed to push The Trade Desk's technical capabilities forward, it turned off a lot of advertisers who were used to its old platform. As a result, the transition went more slowly than expected, and The Trade Desk lost some ad spend in the process.

Second, Amazon (NASDAQ: AMZN) started encroaching on The Trade Desk's territory, inking deals to sell ad inventory from Netflix, Walt Disney, Spotify Technology, and Roku through its own demand-side platform over the summer. It'll also take over Microsoft's (NASDAQ: MSFT) ad-buying platform this year. Amazon may put pricing pressure on The Trade Desk while taking market share.

With that flurry of bad news, it's no surprise The Trade Desk saw its stock price tank last year. But the market may have overreacted, and investors today have an opportunity to buy the stock at a low price. The digital advertising space is still growing quickly, with 15% annual growth expected through 2030, according to Grand View Research. The Trade Desk should be able to outpace the overall market with its agnostic approach as a neutral party in the adtech space.

With shares trading around $36, the company sports an enterprise value of about $16.9 billion. That's just a 5 times multiple of next year's earnings expectations. Its forward P/E ratio of 17.4 also looks attractive, especially given analysts' 17% earnings growth forecast for 2026. You could buy two shares with your $100 right now, and still have some cash left over to invest.

2. Fortinet

Fortinet (NASDAQ: FTNT) is another beaten-down growth stock, falling about 33% from its high reached at the start of last year. It's an established leader in the next-gen firewall industry, but it's expanding into software-based network security and security operations. Investors have punished the cybersecurity stock based on weak firewall sales and a disappointing product refresh.

Management's fourth-quarter outlook, released in November, further disappointed. The company expects year-over-year revenue growth of just 12%, slowing from the 14% rate of the previous quarter.

Importantly, though, Fortinet is transitioning customers to more of its software products. Secure access service edge (SASE) and security operations (SecOps) billings grew 19% and 33%, respectively, indicating strong growth ahead for the high-margin revenue sources. That should support continued double-digit revenue growth with a bottom line that grows even faster.

However, analysts are only forecasting 11% revenue growth and 9% earnings-per-share growth next year. Those numbers should reaccelerate as SASE and SecOps become a larger portion of the company's overall business and continue to grow quickly. So, with the stock trading around $76, its forward P/E ratio of 26 looks attractive.

3. Marvell Technology

Marvell Technology (NASDAQ: MRVL) plays a pivotal role in AI data centers. Not only are its networking chips essential for moving data quickly between servers, but its custom AI accelerator business is also a major growth driver for the company. That said, the stock received a shock in December, when reports surfaced that Microsoft, one of its biggest custom chip customers, was looking at a rival chipmaker to supply its Maia chip.

But that could be another great buying opportunity for long-term investors. Marvell is facing significant demand for AI accelerators. Microsoft is reportedly looking to buy over $10 billion worth of its Maia chips in 2027, according to Fubon Research. For perspective, Marvell is on track to bring in $8.2 billion this year, and CEO Matt Murphy said it's targeting $10 billion next year. While Microsoft seeking a second source for its Maia chips could hurt revenue growth somewhat, Marvell's trajectory remains strong.

Still, Marvell holds contracts with all four major hyperscalers, and it's adding smaller companies it calls "emerging hyperscalers" as well. Meanwhile, its networking business is set to grow as AI data centers continue to get bigger and bigger. Its Celestial AI acquisition should help it capture a larger share of the important interconnect market. As such, the company should experience very strong revenue growth and even better earnings growth as it scales.

With the stock trading for around $80, its forward P/E ratio is about 28.4. That's despite expectations for 22% revenue growth and 27% earnings growth next year as it continues to benefit from growing demand for custom compute and networking chips. An expanding customer base should ensure it can continue that level of growth for years to come. At this price, it's a no-brainer.

Adam Levy has positions in Amazon, Microsoft, Netflix, Roku, and Walt Disney. The Motley Fool has positions in and recommends Amazon, Fortinet, Microsoft, Netflix, Roku, Spotify Technology, The Trade Desk, and Walt Disney. The Motley Fool recommends Marvell Technology and recommends the following options: long January 2026 $395 calls on Microsoft and short January 2026 $405 calls on Microsoft. The Motley Fool has a disclosure policy.