Top Five S&P 500 Gainers In 2025: The Highest-Performing Stock Rose Nearly 600% In Value This Year

Sandisk, Micron, Seagate, Western Digital Corp., and Robinhood are the top five percentage gainers on the S&P 500 index in 2025.

• Strong rallies in technology and communication services stocks have driven the index up about 17.4% year to date.
• Investors were drawn to companies positioned to benefit from demand for AI, cloud computing, and high-capacity data storage.
• Sandisk was the top performer, with shares surging more than 596% this year.

As 2025 winds down, the S&P 500 hovers near record highs and is on pace for its third straight year of gains. Despite weakness in sectors such as real estate and consumer staples, broad strength in technology and communication services propelled the index up roughly 17.4% year-to-date.

Investors were particularly drawn to companies positioned to benefit from surging demand for artificial intelligence, cloud computing, and high-capacity data storage, as enterprises and hyperscale data centers ramp up infrastructure to support next-generation workloads.

Here’s a look at five stocks from the S&P 500 index that posted the biggest percentage gains this year.

1. Sandisk Corp. (SNDK): Since debuting on the public market at $35.06 on February 13, Sandisk shares have soared more than 596% year-to-date, powered by a string of blowout quarterly results. The company has beaten Street expectations in all three quarters since its listing.

In the most recent quarter, revenue climbed to $2.38 billion, well above the $2.12 billion consensus estimate, while reported earnings per share topped forecasts by 37%. The firm’s management reinforced that momentum with upbeat second-quarter guidance, projecting EPS of $3.00 to $3.40 on revenue of $2.55 to $2.65 billion. Gross margins are also expected to expand meaningfully, rising to the 41% to 43% range.

Earlier this month, JPMorgan began coverage of SanDisk with a ‘Neutral’ rating and set a $235 price target, according to The Fly. The bank highlighted Sandisk’s exposure to the AI-driven enterprise SSD “supercycle” and noted its “structurally advantaged” cost position through the Kioxia joint venture.

2. Western Digital Corp. (WDC): Shares have gained 298.7% year to date, reflecting a series of strategic and operational tailwinds. In February, the company completed the spin-off of its flash business and laid out its roadmap as a pure-play HDD company, highlighting growth tied to AI-driven workloads, the rollout of heat-assisted magnetic recording (HAMR) technology, and the critical role of hard drives in hyperscale data center infrastructure. The momentum continued in May with the announcement of a $2 billion share repurchase program.

Operationally, results have remained strong. Fiscal first-quarter (Q1) 2026 revenue rose 27% to $2.82 billion, driven by robust demand from cloud storage customers. The company’s management expects that strength to carry into the second quarter, supported by sustained data center demand and higher-capacity drives. 

Adding to the bullish outlook, Morgan Stanley earlier this month lifted its price target on Western Digital to $228 from $188 and reiterated an “Overweight” rating on the stock.

3. Micron Technology (MU): The stock has surged roughly 250% in 2025, driven by a standout fiscal year that delivered record revenue, margins, and earnings. Growth was fueled by strong demand from AI and data center customers, with high-bandwidth memory (HBM) emerging as a key catalyst. Momentum continued into fiscal 2026, with Micron reporting a record first-quarter revenue of $13.64 billion, up 57% year-over-year. 

Following these results, Deutsche Bank raised its price target to $300 from $280 and reiterated a “Buy” rating, describing the quarter and outlook as “stunning.” The firm highlighted Micron’s execution, disciplined spending, and strong pricing as drivers of a broader shift in the memory industry. Micron also shipped 1-gamma DRAM, ramped G9 NAND production, and introduced industry-first data center SSDs.

4. Seagate Technology Holdings (STX): The company’s 2025 performance was marked by soaring demand for mass-capacity storage amid rising AI workloads and cloud spending. Its stock climbed nearly 226% year-to-date. Fiscal Q1 2026 revenue rose 21% to $2.63 billion, fueled by strong demand for high-capacity HAMR drives. 

The Mozaic platform, offering 30TB–36TB drives, has already been qualified by major cloud customers, with broader adoption underway. In May, Seagate authorized a $5 billion share repurchase. 

Citi recently raised its price target to $320 from $275, citing constrained supply, sustained pricing, and AI-driven storage demand through 2027.

5. Robinhood Markets (HOOD): Robinhood also had a stellar 2025, with shares up over 215%. Strong trading volumes, especially in crypto and AI-related assets, combined with consistent revenue and earnings growth, drove the surge. Product innovation, including prediction markets and the Robinhood Gold Card, boosted engagement, while S&P 500 inclusion enhanced institutional visibility. 

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