The S&P 500 has had a very solid 2025. With just a couple of trading days left in the year, the index is up almost 17%. That's not bad considering the average annual gain for the S&P 500 is about 10%. Obviously, many stocks outperformed the broader index, some by a lot.
But which S&P 500 stock has had the best 2025?
The answer is Sandisk (SNDK +2.09%). The stock's price is up a whopping 570% in 2025 after going public in February at $38.50 a share. It currently trades at about $241 a share.

NASDAQ: SNDK
Key Data Points
Headquartered in Milpitas, California, in the heart of Silicon Valley, Sandisk makes data storage devices based on NAND flash technology, which is a type of nonvolatile storage technology that can retain data without a power source. "NAND" combines the words "Not" and "And" and refers to the logic gate that is critical to the devices.
Sandisk products made with NAND technology include memory cards, USB flash drives, and solid-state drives.
There's a memory device shortage
There's currently a global supply shortage of memory and storage chips, as artificial intelligence (AI) and consumer electronics firms continue to compete for dwindling supplies.
Source: Getty Images.
And Sandisk had a huge fiscal first quarter. Revenue rose 21% to $2.3 billion, above the $2.1 billion analysts expected. Earnings of $1.22 were more than double the consensus $0.58 Wall Street looked for.
The stock popped 15% the day after the Nov. 6 earnings announcement. What a year for Sandisk.





