These Were the S&P 500's Top Performers in 2025. Are They Still Good Buys in 2026?

In the past three years, tech stocks been among the hottest buys due to the growth in artificial intelligence (AI). Last year was no exception, but it wasn't the data analytics stocks or chip stocks that performed the best. Instead, it was companies involved with selling memory and storage products that did the best.

The three hottest stocks on the S&P 500 last year were Sandisk (NASDAQ: SNDK), Western Digital (NASDAQ: WDC), and Micron Technology (NASDAQ: MU). Here's how well they did, how their valuations look today, and if they are still good buys for 2026.

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Sandisk: up 559%

Sandisk was a late addition to the S&P 500, joining the index back in November. And it didn't trade for a full year, either, as it spun off from Western Digital back in February. However, even with a shortened timeframe, it soared an incredible 559% in 2025.

Western Digital acquired Sandisk in 2016 but the two have now gone their separate ways. Sandisk's focus is on flash drives, memory cards, and solid-state drives (SSDs). Its products are most suitable for high-speed storage and mobility. In its most recent quarterly results, which went up until Oct. 3, 2025, the company's revenue totaled $2.3 billion, which was up 23% year over year. Sandisk says it has "engagement with five major hyperscale customers," as it is clearly benefiting from a surge in AI-powered memory and storage needs.

Sandisk's market cap of $40 billion may look enticing for investors seeking the next big AI play. But despite the recent growth, the company's net income fell by 47% in its most recent quarter with interest expenses weighing on its bottom line.

Although the stock looks modestly valued, trading at forward price-to-earnings (P/E) multiple of 20 (based on analyst expectations), investors should tread carefully with the stock given its dependence on hyperscalers, AI demand, and its lack of bottom-line growth. I'd hold off on buying the stock given the rosy expectations that are priced into its valuation and its light margins.

Western Digital: up 238%

Western Digital's business is also centered around storage, but its primarily around hard disk drives and external storage which can be crucial for backing up data. In its most recent quarter, which coincides with Sandisk's, Western Digital achieved a higher growth rate of 27%, with its top line rising to $2.8 billion. And unlike Sandisk, its profits soared from $493 million to nearly $1.2 billion.

With a higher gross margin, the stock looks to be in a better position to grow both its top and bottom lines in unison. Shares of Western Digital soared by 238% last year, which is good enough for second spot on this list. And today, it trades at a forward P/E of 25.

Western Digital's business could provide investors with greater stability and predictability in the long run given the ongoing need for data storage and backups through its high-storage devices. If you're bullish on AI, this can still make for a good quality tech stock to own this year as Western Digital is a trusted brand in storage solutions that can experience much more growth in the long run.

Micron Technology: up 198%

Rounding out this list is Micron Technology, which also sells memory and storage products. Business has been going so well for the business due to AI that it announced last month that it will be exiting its Crucial consumer business.

The company says the move will enable to better focus on "larger, strategic customers in faster-growing segments." It's unfortunate that it can't keep doing both. But becoming leaner and more focused on business products, including selling dynamic random-access memory (DRAM) that's used in phones and computers, could position it better to benefit from AI-related growth opportunities.

The stock soared 198% in 2025 and according to analyst projections, it may be the best deal on this list, as it trades at a forward P/E of just 10. By focusing more directly on business customers, Micron could be in a great position to rise higher.

Its growth rate for its most recent period (which ended on Nov. 27, 2025) was 57%, and with some terrific profit margins of around 40%, it looks like the best stock to buy here. For growth investors, Micron may be a slam-dunk buy given its focus on business customers moving forward.

David Jagielski, CPA has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.