SanDisk emerges as S&P 500’s top performer after Western Digital spin-off

Less than a year after becoming an independent company, SanDisk has surged past every stock in the S&P 500, driven by booming AI-led demand for NAND flash memory, improving fundamentals and growing exposure to data centre customers.

SanDisk has delivered a standout performance since its separation from Western Digital, rapidly establishing itself as one of the most closely watched stocks in the US market. Following its return to public markets earlier this year, the flash memory specialist has outpaced not only its former parent but also major technology heavyweights, emerging as the best-performing stock in the S&P 500.

Western Digital announced its plan to split its flash and hard drive businesses in October 2024. As part of the restructuring, shareholders received stock in the newly listed SanDisk, which made its market debut in February. The listing marked a return for the brand, which had previously traded independently before being acquired by Western Digital in 2016.

A remarkable stock market run

Since relisting, SanDisk’s shares have climbed more than 570 percent, leaving peers such as Western Digital and Seagate far behind. After an initially volatile debut session, the stock moved into a consolidation phase before entering a sharp rally that saw prices multiply several times over in just a few months.

Analysts attribute the sustained momentum to strong earnings performance, a tight supply environment in the memory market and growing optimism around artificial intelligence infrastructure spending. Inclusion in the S&P 500 later in the year also helped stabilise the stock during periods of broader market weakness.

Fundamentals strengthen with AI demand

SanDisk’s financial performance has shown steady improvement, with revenue and margins trending higher since the latter half of 2025. Demand from edge computing customers accounted for the largest share of revenue, followed by consumer products and data centre deployments.

The company has been increasingly focused on the data centre segment, where demand has accelerated alongside investments in AI and cloud infrastructure. Management has highlighted strong traction for its enterprise storage portfolio and ongoing qualification processes with major hyperscale customers.

Positioning for long-term growth

Industry forecasts point to sustained expansion in the global NAND flash memory market over the coming decade, supported by AI workloads, cloud adoption and data-intensive applications. SanDisk has signalled plans to deepen relationships with hyperscalers and large storage partners, aiming to capitalise on this growth cycle.

Analyst views turn selective

Despite the sharp rally, analyst sentiment remains largely constructive. Most brokerage firms continue to rate the stock as a buy or hold, though some have flagged valuation concerns after the rapid rise. While a few institutions have tempered their near-term expectations, they broadly agree that SanDisk is well positioned to benefit from an early-stage NAND upcycle.

For now, SanDisk’s post-spin-off surge stands as a rare example of a corporate breakup unlocking value at scale, with investors closely watching whether fundamentals can continue to justify its meteoric ascent.