The S&P 500 is on the verge of closing out another formidable year for investors, with the SPDR S&P 500 ETF (NYSEARCA: SPY) delivering a return of 17.22% heading into the final trading day of the year. And the year was defined by a set of powerful themes. Perhaps most notable was the massive memory supercycle and the continued maturation of AI infrastructure. As the early excitement around AI software cooled, capital rotated aggressively toward the physical hardware required to store, move, and process unprecedented volumes of data.
And with a global shortage of high-end storage hardware components, three stocks in the semiconductor and data storage ecosystem dominated the index, outperforming even the Magnificent Seven.
As we head into the final trading session of the year, here is a look at the top three performing S&P 500 stocks of 2025. Unsurprisingly, all three were direct beneficiaries of the red-hot AI hardware theme.
1st Place: SanDisk, Up 567% YTD
SanDisk (NASDAQ: SNDK) stands as the undisputed top performer of 2025. After completing its spin-off from Western Digital in February and earning inclusion in the S&P 500 in November, the stock surged an astonishing 567% year-to-date (YTD).
SanDisk develops and manufactures data storage solutions built on NAND flash technology. It’s a segment that has become increasingly critical to AI workloads spanning data centers, mobile devices, and edge computing. The rally was driven by a near-perfect storm, combining a global shortage of NAND flash memory with rapidly accelerating demand for fast, local storage tied to the rise of AI at the edge.
As a pure-play flash provider, SanDisk was uniquely positioned to benefit from soaring prices, which roughly doubled during the second half of the year. That operating leverage showed up clearly in the results. SanDisk reported fiscal first-quarter fiscal year 2026 (FY2026) earnings on Nov. 6, posting earnings per share of $1.22, more than double the consensus estimate of 58 cents. Revenue climbed 22.6% year-over-year (YOY) to $2.31 billion, well ahead of estimates, firmly cementing SanDisk’s leadership role in the memory supercycle.
2nd Place: Western Digital, Up 290% YTD
Close behind is former parent company Western Digital (NASDAQ: WDC), which had gained 290% ahead of the final trading session. The decision to separate from SanDisk proved to be a strategic turning point, allowing Western Digital to fully concentrate on its enterprise hard disk drive business.
While flash memory dominates consumer devices, Western Digital’s ultra-high-capacity HDDs, now reaching 32 terabytes and beyond, have become foundational infrastructure in large-scale AI data centers. These drives are essential for long-term data storage and archival needs tied to AI model training and inference.
Western Digital reported fiscal first-quarter FY2026 earnings on Oct. 30, delivering earnings per share of $1.78, topping consensus estimates by 21 cents. Revenue rose 27.4% YOY to $2.82 billion, again exceeding expectations. The results underscored how demand for enterprise storage remains structurally strong, even as the broader semiconductor cycle matures.
3rd Place: Micron Technology, Up 247% YTD
Rounding out the top three is Micron Technology (NASDAQ: MU), which delivered a 247% gain before heading into the final day of trading. Micron’s breakout year was driven by its dominance in high-bandwidth memory, a critical component for NVIDIA’s latest Blackwell series GPUs.
As one of only three global suppliers of HBM, Micron benefited from exceptional pricing power throughout 2025. Morgan Stanley analysts described Micron’s fiscal year performance as one of the strongest in the history of U.S. semiconductors, fueled by repeated earnings beats and accelerating demand.
Micron reported fiscal first-quarter FY2026 earnings on Dec. 17, posting earnings per share of $4.78, well above consensus estimates of $3.77. Revenue surged 56.7% YOY to $13.64 billion, exceeding expectations once again. Despite reaching all-time highs in December, Wall Street remains constructive, citing Micron’s forward price-to-earnings ratio of just 7.42, which is still meaningfully below many peers in the broader computing sector. The stock currently carries a consensus Buy rating based on 37 analyst opinions.