By Andrew Moran
Contributing Writer
It was a year for the history books in the U.S. stock market, and optimism is running high as Wall Street turns the page to a new calendar year.
Various themes have dominated the equities arena over the past 12 months, including artificial intelligence, tariffs, and expectations for Federal Reserve policy.
Despite the springtime selloff driven by global uncertainty stemming from the U.S. administration’s trade agenda, investors finished the year with handsome gains.
The blue-chip Dow Jones Industrial Average surged by 14%. The tech-heavy Nasdaq Composite Index soared by 21%. The broader S&P 500 Index climbed by 17%.
Many stocks in the leading benchmark indexes outpaced the broader market, while others failed to participate in the historical bull run.
Here were the best and worst U.S. stocks of 2025.
SanDisk
SanDisk was the top-performing stock in the major indexes, rallying by more than 500%, to firmly above $200.
The company, best known for its USB flash drives and memory cards, made its public debut in February with an IPO priced at $38.50 per share.
Western Digital’s decision to spin off its flash unit in early 2025 reset the narrative around SanDisk, enabling investors to evaluate it independently for the first time in years.
A broad array of other factors contributed to the stock’s meteoric ascent, including shortages of key memory products, strong demand in data centers, and passive buying following its inclusion in the S&P 500 Index.
Western Digital
Data storage firm Western Digital also enjoyed an incredible 2025, posting a gain of about 280%, to above $177.
The decision to transform its business model into concentrating on hard-disk drives eventually paid off for shareholders.
Western Digital has staged a sharp financial recovery since the 2022-23 slump, even reinstating its dividend. The broader industry backdrop amplified the rally, as AI‑related data‑storage demand and a tightening hard‑disk‑drive market pushed momentum in the company’s favor.
Micron Technology
Micron Technology, another major computer memory and data storage company, has seen its shares surge by about 230%, approaching $300.
Like SanDisk and Western Digital, Micron’s shares rocketed amid enormous AI-driven data-center demand, leading to sold-out high-bandwidth memory products and record revenues.
Wall Street is optimistic about Micron’s prospects, with a consensus “buy” rating, according to MarketBeat.
The high-bandwidth memory market is booming, and with the AI buildout expected to continue into 2026, Micron stands to benefit, according to Paul Meeks, managing director and head of technology research at Freedom Capital Markets.
“There’s plenty of upside in the [Micron] stock,” Meeks said in an email. “This is an industry oligopoly — Micron and two South Korean players control roughly 90% of the market — and they’re acting rationally when it comes to adding capacity.
“A $300 price target looks achievable, and it could even go higher.”
Seagate Technology
Seagate Technology Holdings was another data storage company that posted a 200% gain over the past year.
AI workloads have created a supply-demand imbalance in storage data, and the company does not plan to accelerate output to close the gap, according to Seagate CFO Gianluca Romano.
“We see actually the gap between supply and demand getting a little bit bigger every quarter — that means demand is shifting more into the future,” Romano said during an Oct. 28 earnings call.
Seagate’s inclusion in the Nasdaq‑100 Index provided an additional boost, as index‑tracking funds stepped in with automatic buying.
Palantir Technologies
Shares of Palantir Technologies increased by 145% this year, making it one of the top-performing stocks of 2025.
Palantir builds data integration and analytics platforms for corporations and governments — intelligence, law enforcement, and military— to coalesce a treasure trove of information.
Explosive demand for its AI platform drove the stock to more than $180.
Most notably, Palantir secured a $10 billion contract with the U.S. Army this past summer. But it also expanded its partnerships with a number of major companies, including Airbus, Merck, Morgan Stanley and Nvidia.
Trade Desk Inc.
What a difference a year can make.
In 2024, Trade Desk, a digital advertising technology company, was one of the best-performing stocks on Wall Street.
This year, it was the worst-performing stock among the major indexes, plunging by 67% amid a cascade of headwinds.
First, the company reported disappointing financials, with slowing revenue growth, shrinking margins and earnings that fell short of market expectations.
Strengthening competition in the retail media ecosystem from Amazon, Google and Meta further weighed on its prospects.
Still, analysts are holding out hope, with a consensus “moderate buy” rating and a 12-month upside of 99%, according to MarketBeat.
Deckers Outdoor
Footwear designer and distributor Deckers Outdoor had a disappointing 2025, tanking by almost 50% following a momentous 2024.
While multiple factors impacted Deckers Outdoors — lethargic investor sentiment, valuation concerns and insider selling — the broader apparel industry has been depressed.
Shares of Nike and Adidas, for example, declined by 17% and by 29%, respectively.
New U.S. tariffs, cost-conscious shoppers, valuation changes and evolving retail landscape have adversely affected the apparel industry.
Gartner
Gartner, an advisory and research firm that works with corporations and government agencies, tumbled by 47% this year to about $250 per share.
The company’s decline in 2025 was multifaceted, specifically slowing contract growth and AI.
At the start of President Donald Trump’s second term in the White House, the U.S. government canceled scores of consulting contracts, including those with Gartner. This forced the company to reduce its full-year revenue forecasts.
Meanwhile, Gartner’s business model is being disrupted by AI analytics and research tools, as other firms turn to low-cost alternatives or build their own systems.
Lululemon Athletica
Rumors of yoga pants’ death in the U.S. market may be greatly exaggerated, but Lululemon Athletica’s slipping sales were very real and a key concern for investors.
The athleisure giant’s stock dropped by 43% this year, to $212 — remarkably down from $511 in December 2023.
“Lululemon shares as well as investors’ patience have been stretched thin,” Jay Woods, chief market strategist at Freedom Capital Markets, said in an email. “Rising import costs and tariff pressures have eroded margins. There has also been a weaker demand for the athleisure giant.”
The company reported a 3% year-over-year decline in U.S. sales in the third quarter, while North American revenue growth has stalled. Downwardly adjusted earnings guidance and increasing operating costs have spooked investors and market watchers.
Molina Healthcare
It has been a steep slide for Molina Healthcare since the summer, with the stock off by about 40% for the year.
A wide range of factors has led to the stock’s steady decline since its March 2024 peak.
Most notably, medical costs have rocketed across multiple segments. The share of premiums spent on medical claims has jumped significantly over the past year because of the Affordable Care Act, causing margins to collapse. In addition, broad-based inflationary pressures and regulatory hurdles have added to the company’s troubles.
Molina has also witnessed falling membership levels. In a single quarter, the company lost 118,000 customers.
This has caused the managed care company to fall short of earnings and repeatedly slash its full-year earnings outlook.
