Sandisk vs. Micron: Which AI Memory Stock Is the Better Buy After Their Monster Runs?

Few corners of the market have run up as sharply as memory chips. Shares of Sandisk (NASDAQ: SNDK) have soared more than 700% in 2026 as of this writing, while Micron Technology (NASDAQ: MU) has more than tripled this year and recently crossed $1 trillion in market value. Both have climbed for the same reason: an artificial intelligence (AI) build-out so hungry for storage and memory that supply can't keep up, pushing prices for NAND flash and dynamic random access memory (DRAM) sharply higher.

But which of these two stocks is the better buy today?

Image source: The Motley Fool.

Sandisk: a pure bet on the flash shortage

In its fiscal third quarter of 2026 (the period ended April 3, 2026), the flash specialist's revenue jumped 97% from the prior quarter and 251% from a year earlier, to $5.95 billion. Non-GAAP (adjusted) earnings per share reached $23.41, up from $6.20 in fiscal Q2.

Powering its growth, Sandisk's data center revenue climbed 233% sequentially.

What may matter more for a notoriously cyclical business is how much of that demand Sandisk has nailed down. Fortunately, it has signed five multiyear supply agreements that lock in firm customer commitments, covering more than a third of its fiscal 2027 output and backed by over $11 billion in enforceable financial guarantees.

"Data center has become our fastest-growing market, and the workloads driving that demand, including inference, reasoning, and agentic systems, represent a structural and durable shift in how the world's most consequential technology is built and deployed," said Sandisk CEO David Goeckeler in the company's fiscal third-quarter earnings call.

Sandisk is also returning cash to shareholders. It recently authorized a $6 billion share buyback. And it carries no debt.

Micron: the broader memory play

Micron's momentum is similarly spectacular. In its fiscal second quarter of 2026 (the period ended Feb. 26, 2026), the memory and storage maker posted revenue of $23.86 billion, nearly triple the year-ago figure, with adjusted earnings per share of $12.20 and a record gross margin of about 75%. DRAM made up $18.8 billion of that, or 79% of revenue, while NAND accounted for the rest.

Within its DRAM business, HBM -- the dense, stacked chips that pair with AI accelerators from the likes of Nvidia -- is the scarcest, highest-value product in the memory market, and Micron has said its HBM output for 2026 is already sold out.

And the company notably began shipping its newest HBM for Nvidia's next-generation Vera Rubin platform earlier this year.

"Both AI and traditional server demand are constrained by lack of adequate DRAM and NAND supply," said Micron CEO Sanjay Mehrotra in the company's fiscal second-quarter earnings call.

Looking ahead, Micron is guiding for an even bigger fiscal third quarter, with revenue of about $33.5 billion -- a single quarter that would exceed its revenue for any full year through fiscal 2024.

But this growth story comes with high costs. Micron expects to spend more than $25 billion on new plants and equipment this fiscal year.

The better buy

On valuation, Sandisk initially looks more expensive, with a price-to-earnings ratio of about 69 as of this writing, while Micron's is 49. But these valuation metrics don't tell the full story. Since the two companies are growing so quickly, it's probably better to view them based on their forward price-to-earnings ratios, or valuation multiples that compare their prices to analysts' consensus forecasts for earnings per share over the next 12 months. By this measure, Sandisk and Micron have forward price-to-earnings multiples of about 11 and 10, respectively, making them look priced very similarly based on their future prospects.

So, which is the better buy?

Overall, I think Micron is the better bet. Its DRAM and HBM exposure puts it in a vital part of the AI memory market, and it generates enormous cash even while funding a heavy build-out. Meanwhile, Sandisk's business is arguably narrower than Micron's, leaving it with greater downside risk if the cycle turns. And after a run-up this big, I'd rather own the broader business.

Daniel Sparks and his clients have no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Micron Technology and Nvidia. The Motley Fool has a disclosure policy.