Last week delivered some serious gains for large-cap investors, and if you had any of these ten stocks in your portfolio, you were probably smiling. Healthcare names dominated the list, but there were a few surprises mixed in too.

The Blockbuster Winner

Exact Sciences Corporation (EXAS) absolutely exploded higher, gaining 48.97% after Abbott Laboratories (ABT) agreed to acquire the company for $105 per share in a deal valued at roughly $20 billion. When a healthcare giant writes a check that big, investors tend to celebrate.

Biotech Breakthroughs and Bullish Calls

Jazz Pharmaceuticals plc (JAZZ) climbed 3.75% following positive phase 3 data for its Ziihera combination therapy. The results were compelling enough that multiple analysts bumped up their price targets on the stock.

Natera, Inc. (NTRA) jumped 12.90% this week. UBS analyst Elizabeth Garcia maintained her Buy rating while raising her price forecast from $218 to $280, a substantial vote of confidence.

Guardant Health, Inc. (GH) gained 11.57% during the week, though no specific catalyst was cited for the move.

Regeneron Pharmaceuticals, Inc. (REGN) rallied 9.09% after the FDA approved Eylea HD for macular edema following retinal vein occlusion. Regulatory approvals like this can unlock significant revenue opportunities, and the market clearly liked what it saw.

Earnings Winners and Strategic Moves

Amer Sports, Inc. (AS) surged 12.86% after reporting third-quarter results that topped expectations and raising its fiscal 2025 guidance above analyst estimates. The strong performance prompted several analysts to increase their price targets.

James Hardie Industries plc. (JHX) gained 12.39% on better-than-expected second-quarter financials. The company also named Ryan Lada as its new CFO, adding some fresh leadership to the mix.

Solventum Corporation (SOLV) rose 9.09% after announcing plans to acquire Acera Surgical for $725 million in cash, plus up to $125 million in contingent payments. The company's board also authorized a $1 billion stock buyback program, signaling confidence in its outlook.

Tech and Telecom Movers

Lumentum Holdings Inc. (LITE) gained 9.38% after Mizuho analyst Vijay Rakesh initiated coverage with an Outperform rating and set a price target of $290.

Alphabet Inc. (GOOGL) picked up 4.9% despite ongoing regulatory headaches. The company pushed back hard against the Department of Justice's proposal to break up Google Ad Manager, calling it "unworkable" and warning it would create chaos for advertisers and publishers. Google said it remains committed to finding a resolution that addresses the court's concerns without damaging American business growth.

Whether these gains have staying power depends on follow-through—earnings execution, deal closings, and how well these companies navigate their respective challenges. But for one week at least, these ten stocks gave investors plenty to cheer about.