S&P 500 Winners and Losers This Week – Sept. 11, 2026

NEW YORK – September 11, 2026 (STL.News) Wall Street ended a volatile, holiday-shortened trading week with a strong Friday rebound, but the rally was not enough to erase losses accumulated earlier in the week. Beneath the headline indexes, individual S&P 500 stocks showed dramatic divergences, with technology and communications-related companies posting some of the strongest gains while several health care, consumer and technology names fell by double digits.

The S&P 500 finished Friday at 7,656.98, gaining 0.86% for the session, but ended the week approximately 0.8% lower. The Nasdaq Composite gained 0.96% Friday but lost approximately 0.7% for the week, while the Dow Jones Industrial Average rose 0.98% Friday and declined approximately 1.6% for the week.

The Russell 2000, which tracks smaller U.S. companies and is not part of the S&P 500, fell about 2.4% for the week. Despite the declines, the major indexes remained solidly positive for 2026, with the S&P 500 up approximately 11.9% for the year through Friday.

The week’s individual S&P 500 winners and losers demonstrate just how wide the performance gap has become between companies benefiting from specific catalysts and those being punished for earnings disappointments, weaker outlooks or other company-specific concerns.

S&P 500 Top Five Performers

Based on the week’s S&P 500 performance data, the five leading stocks were:

The ranking puts Lumentum Holdings at the top with a gain of approximately 9%, followed by Hewlett Packard Enterprise at 7.15%. TKO Group gained 5.89%, Edison International advanced 4.95%, and Ciena rounded out the five leaders at 4.24%. Corning narrowly missed the top five with a gain of approximately 4.22%.

Lumentum Leads the S&P 500

Lumentum Holdings, ticker LITE, emerged as the week’s top S&P 500 performer with a return of approximately 9.02%.

The optical and photonics technology company’s top position is notable because Lumentum operates in areas increasingly tied to the enormous infrastructure requirements created by artificial intelligence and data centers. High-speed optical connectivity has become an important part of the infrastructure needed to move increasingly large quantities of data between servers and computing systems.

The stock’s strength was especially pronounced early in the shortened week. Historical trading data show Lumentum recorded a major advance on Tuesday, helping establish its position among the week’s leaders.

Lumentum’s performance also fits into a broader market theme: investors continue to search beyond semiconductor manufacturers for companies positioned to benefit from the massive capital expenditures being committed to AI infrastructure.

Hewlett Packard Enterprise Surges on AI Optimism

Hewlett Packard Enterprise, ticker HPE, finished second with a weekly gain of approximately 7.15%, but its Friday performance was even more striking.

HPE shares surged approximately 12% Friday, reaching record territory as investors responded to renewed evidence that spending on artificial intelligence infrastructure remains exceptionally strong.

The catalyst extended well beyond HPE itself.

Oracle’s latest results reinforced expectations for enormous spending on cloud computing and AI infrastructure. That sent investors searching for hardware, networking and server companies likely to benefit from the buildout.

Dell Technologies also surged approximately 12% Friday, while HP posted a large gain. Dell did not make the week’s top five because losses earlier in the week offset much of Friday’s advance.

The distinction is important. Friday’s biggest winners were not necessarily the week’s biggest winners.

For HPE, however, Friday’s rally was large enough to propel the stock into second place for the week.

TKO Group Ranks Third

TKO Group Holdings, ticker TKO, finished third with a weekly return of approximately 5.89%.

TKO is the sports and entertainment company whose portfolio includes major combat-sports and entertainment properties. Its inclusion among the week’s strongest S&P 500 stocks also shows the rally wasn’t confined entirely to technology.

Historical pricing data show TKO experienced a particularly strong Tuesday session, providing much of the momentum behind its weekly advance.

As investors become more willing to assign premium valuations to businesses with scarce entertainment content, global audiences, and valuable media rights, TKO remains an important stock to watch beyond the technology-driven portion of the market.

Edison International Advances

Edison International, ticker EIX, ranked fourth with a weekly return of approximately 4.95%.

The utility company’s appearance among the leading stocks is particularly interesting because utilities often trade differently from high-growth technology companies.

Edison shares were highly volatile during the week. Historical market data show a sharp advance Tuesday followed by declines during subsequent sessions.

Nevertheless, the early-week move was sufficient to place Edison among the strongest S&P 500 performers in the weekly ranking.

Ciena Rounds Out the Top Five

Ciena, ticker CIEN, rounded out the list with a gain of about 4.24%.

Like Lumentum, Ciena provides exposure to networking and communications infrastructure. The company supplies technology used by telecommunications companies, cloud providers, and other organizations requiring high-capacity networks.

Ciena’s presence alongside Lumentum is noteworthy because it reinforces one of the market’s larger investment themes: the AI boom increasingly involves far more than GPU manufacturers.

AI data centers require servers, networking equipment, optical components, power infrastructure, cooling systems and enormous amounts of electrical generation and transmission capacity.

Historical pricing data show Ciena’s strongest move came Tuesday, when the stock advanced sharply.

S&P 500 Worst Five Performers

The other side of the market was considerably more painful.

For the Sept. 4 through Sept. 11 measurement period, the five worst-performing S&P 500 stocks were:

The scale of those declines is remarkable considering that all five companies are members of America’s benchmark large-cap stock index.

CooperCompanies Plunges Nearly 23%

The week’s biggest S&P 500 loser was Cooper Companies (COO), down about 22.98%.

The medical-device company suffered a major selloff after reporting weaker-than-expected quarterly revenue and reducing its full-year outlook. Shares plunged about 15% during Thursday’s session alone.

That type of reaction illustrates the risk facing highly valued companies when results or forward guidance fail to meet Wall Street expectations.

Investors frequently react more aggressively to changes in a company’s future outlook than to the quarter that has already been completed. A lowered forecast can force analysts to revise earnings models, price targets and valuation assumptions simultaneously.

By week’s end, Cooper Companies had lost almost one-quarter of its market value on a percentage basis compared with the previous Friday.

Casey’s Falls After Same-Store Sales Disappoint

Casey’s General Stores, ticker CASY, ranked second among the week’s biggest losers, falling approximately 16.46%.

The convenience-store operator’s shares came under heavy pressure following its fiscal first-quarter results.

Casey’s reported earnings of $7.37 per share and revenue of $5.68 billion, both exceeding analyst expectations cited by Investopedia. But investors focused heavily on comparable-store trends.

Inside same-store sales rose about 3.2%, below expectations of roughly 3.8%, while same-store fuel gallons fell about 0.3%. The stock then fell nearly 15% in a single session.

The reaction shows that beating headline earnings estimates does not guarantee a stock-price increase.

Markets price stocks based largely on expectations about the future. Investors may therefore punish a company even when reported earnings exceed forecasts if underlying operating indicators suggest slowing growth.

FactSet Drops 14%

FactSet Research Systems, ticker FDS, was the third-worst S&P 500 performer, falling approximately 14% over the measured period.

FactSet occupies an important position within financial markets because its data, analytics and research systems are widely used by investment professionals.

The magnitude of the decline put FactSet well ahead of most S&P 500 companies on the downside and highlights another important theme facing information and software companies: investors are closely scrutinizing growth expectations, valuations and the potential disruption and opportunity created by artificial intelligence.

PTC Falls More Than 12%

PTC, ticker PTC, ranked fourth, declining approximately 12.55%.

PTC develops industrial software used in product development, engineering, and manufacturing.

The decline was substantial enough to place the company among a relatively small group of S&P 500 stocks that lost double digits during the measurement period.

Amgen Rounds Out Bottom Five

Biotechnology giant Amgen, ticker AMGN, completed the bottom-five ranking with a decline of approximately 12.48%.

Amgen’s presence makes the bottom five notably diverse. The list includes medical devices, convenience retail, financial information, industrial software and biotechnology.

That diversity indicates this was not simply a collapse within one troubled industry. Company-specific developments and shifting investor expectations created unusually large price movements across several sectors.

Other major laggards included Gartner, Stryker, Moderna, Workday and Howmet Aerospace, each posting substantial declines over the Sept. 4-to-Sept. 11 measurement period.

Friday Rally Could Not Save the Week

Friday offered investors some relief.

The S&P 500 rose 0.86%, the Nasdaq Composite gained 0.96%, and the Dow advanced 0.98%. Nine of the S&P 500’s 11 major sectors finished higher.

Yet the rebound came after four straight losing sessions and was not enough to push the major indexes into positive territory for the week.

Oil played an important role in market sentiment.

Crude prices eased Friday, but oil remained approximately 9% higher for the week amid geopolitical tensions and disruptions affecting global energy markets. Higher energy prices can feed directly and indirectly into inflation by raising transportation, manufacturing, and operating costs across the economy.

Investors were simultaneously digesting inflation data and reconsidering the outlook for Federal Reserve monetary policy.

Interest-rate futures by Friday were indicating a nearly 90% probability of a Federal Reserve rate increase, according to Reuters, compared with about 72% a day earlier.

That matters for stocks because higher interest rates increase borrowing costs and raise the discount rate investors apply to future corporate earnings. Growth stocks with valuations based heavily on profits expected years into the future can be especially sensitive to rate changes.

What Investors Should Watch Next Week

The week’s winners and losers tell two very different stories.

On the winning side, Lumentum, HPE and Ciena demonstrate how investors continue to seek companies positioned somewhere within the enormous AI and data-center capital-spending cycle.

Oracle’s results helped reinforce that narrative Friday, triggering large rallies across several technology infrastructure companies.

On the losing side, Cooper Companies and Casey’s demonstrate how quickly investors can punish companies when earnings reports reveal disappointing sales trends, or management reduces expectations.

The broader market now enters another potentially important week with the Federal Reserve, inflation, Treasury yields, oil prices and geopolitical developments all capable of moving stocks.

Friday’s rebound showed that investors remain willing to buy selected stocks aggressively when the fundamental story appears favorable.

But the S&P 500’s weekly decline — combined with nearly 23% separating the week’s biggest loser from its previous-week level — demonstrates that beneath the major indexes, volatility remains significant.

For investors, the central question next week is whether Friday’s recovery marks the start of renewed upward momentum or a one-day rebound in a market increasingly concerned about inflation, higher interest rates, and geopolitical risk.

Disclaimer: This article is for informational purposes only and does not constitute investment advice, a recommendation to buy or sell securities, or financial planning guidance. Stock prices can change rapidly, and past performance does not guarantee future results.