S&P 500 — daily market movers
Macro backdrop
A post-hike relief rebound. The S&P 500 rose +1.14%, the Nasdaq +1.69% and the Dow +0.61%, recovering from the prior session's sell-off after the Fed raised rates 25bps to 3.75-4% on Sept 16 — its first hike since 2023 — and signaled more increases ahead. Easing Treasury yields and oil prices helped risk appetite return, with money rotating back into AI hardware and semiconductors.
Top 10 gainers
| # | Ticker | Company / business | Change | Likely Driver |
|---|---|---|---|---|
| 1 | GNRC | Generac Backup power generators and home/industrial energy storage systems | +18.34% | Surged on a reported ~$8B agreement to supply Amazon with backup generators to power its data centers (initial commitment near $2.4B). |
| 2 | SMCI | Super Micro Computer High-performance AI servers and data-center hardware | +9.50% | Rose with a broadening AI-server hardware bid, part of a multi-session semiconductor and data-center rebound. |
| 3 | MRNA | Moderna mRNA vaccines and oncology (cancer vaccine) research | +8.55% | Extended a strong cancer-vaccine trade on positive oncology data; the momentum has driven a roughly triple-digit monthly gain. |
| 4 | HPE | Hewlett Packard Enterprise Enterprise servers, storage, networking and AI infrastructure | +7.69% | Climbed on strong AI-infrastructure and enterprise-server demand as the hardware bid broadened. |
| 5 | INTC | Intel Designs and manufactures CPUs and semiconductors | +7.67% | Jumped on multiple analyst price-target hikes and buzz around a potential SK Hynix-related partnership. |
| 6 | SWKS | Skyworks Solutions RF and analog chips for smartphones and wireless devices | +6.69% | Rallied as progress toward its merger with Qorvo appeared to clear, alongside the broader chip rebound. |
| 7 | AMD | Advanced Micro Devices CPUs and GPUs for PCs, data centers and AI | +6.36% | Advanced as the semiconductor rebound reached a third straight session on renewed AI-demand optimism. |
| 8 | SNDK | SanDisk Flash memory and data-storage products | +6.21% | Gained with the memory-chip complex as SanDisk, Micron and SK Hynix led a semiconductor rally. |
| 9 | WDAY | Workday Cloud-based HR and finance enterprise software | +6.14% | Rose amid continued AI-momentum optimism, though no single standalone catalyst was confirmed for the day; likely part of a rebound in select software names. |
| 10 | HPQ | HP Inc Personal computers, printers and peripherals | +5.99% | Climbed alongside HPE as the hardware/PC bid broadened, helped by optimism over AI-PC demand. |
- 1. GNRC+18.34%GeneracBackup power generators and home/industrial energy storage systemsSurged on a reported ~$8B agreement to supply Amazon with backup generators to power its data centers (initial commitment near $2.4B).
- 2. SMCI+9.50%Super Micro ComputerHigh-performance AI servers and data-center hardwareRose with a broadening AI-server hardware bid, part of a multi-session semiconductor and data-center rebound.
- 3. MRNA+8.55%ModernamRNA vaccines and oncology (cancer vaccine) researchExtended a strong cancer-vaccine trade on positive oncology data; the momentum has driven a roughly triple-digit monthly gain.
- 4. HPE+7.69%Hewlett Packard EnterpriseEnterprise servers, storage, networking and AI infrastructureClimbed on strong AI-infrastructure and enterprise-server demand as the hardware bid broadened.
- 5. INTC+7.67%IntelDesigns and manufactures CPUs and semiconductorsJumped on multiple analyst price-target hikes and buzz around a potential SK Hynix-related partnership.
- 6. SWKS+6.69%Skyworks SolutionsRF and analog chips for smartphones and wireless devicesRallied as progress toward its merger with Qorvo appeared to clear, alongside the broader chip rebound.
- 7. AMD+6.36%Advanced Micro DevicesCPUs and GPUs for PCs, data centers and AIAdvanced as the semiconductor rebound reached a third straight session on renewed AI-demand optimism.
- 8. SNDK+6.21%SanDiskFlash memory and data-storage productsGained with the memory-chip complex as SanDisk, Micron and SK Hynix led a semiconductor rally.
- 9. WDAY+6.14%WorkdayCloud-based HR and finance enterprise softwareRose amid continued AI-momentum optimism, though no single standalone catalyst was confirmed for the day; likely part of a rebound in select software names.
- 10. HPQ+5.99%HP IncPersonal computers, printers and peripheralsClimbed alongside HPE as the hardware/PC bid broadened, helped by optimism over AI-PC demand.
Common Themes
Eight of the ten gainers cluster in AI infrastructure and semiconductors — SMCI, HPE and HPQ on a broadening server/hardware bid, and INTC, SWKS, AMD and SNDK on a semiconductor rebound now in its third session (SWKS also helped by Qorvo-merger progress, INTC by SK Hynix buzz). WDAY rode continued AI-software optimism. The two outliers had their own catalysts: GNRC on a multi-billion-dollar Amazon data-center generator deal (still AI-power adjacent) and MRNA on its cancer-vaccine trade.
Top 10 losers
| # | Ticker | Company / business | Change | Likely Driver |
|---|---|---|---|---|
| 1 | TMUS | T-Mobile US Wireless telecom carrier | -5.57% | Fell as a premium-plan push clouded near-term subscriber growth and broadband-repricing fears hit the telecom group. |
| 2 | DVA | DaVita Kidney dialysis services provider | -5.56% | Continued a multi-session slide on dialysis margin concerns; no fresh standalone catalyst was confirmed for the day. |
| 3 | PSKY | Paramount Skydance Media, film studios and streaming | -4.67% | Dropped after Barclays downgraded it to Underweight on streaming-growth challenges, with its Warner deal facing state lawsuits. |
| 4 | CPRT | Copart Online salvage and used-vehicle auctions | -3.76% | Slid with no clear company-specific catalyst; likely rotation out of steadier cyclicals into tech and semiconductors. |
| 5 | CSGP | CoStar Group Commercial real-estate data and online marketplaces | -3.51% | Fell with no clear standalone catalyst; a rate-sensitive real-estate-data name pressured by the higher-for-longer rate outlook. |
| 6 | CMCSA | Comcast Cable broadband, media and entertainment | -3.46% | Declined amid broadband-repricing concerns weighing on cable and media names. |
| 7 | BLDR | Builders FirstSource Building materials and construction supply | -3.30% | Hit a fresh 52-week low as the Fed's rate hike and higher-for-longer outlook pressured housing-linked names. |
| 8 | AXON | Axon Enterprise Tasers, body cameras and public-safety software | -3.19% | Extended a roughly 15% weekly drawdown as the high-multiple name kept giving back gains, though analysts remain bullish. |
| 9 | CRM | Salesforce Cloud CRM and enterprise software | -3.07% | Fell to a 19-month low after RBC cut its price target, amid ongoing concerns over AI disruption to enterprise software. |
| 10 | RDDT | Reddit Social-media platform and online communities | -3.03% | Slid with high-multiple software and AI-derivative names; no confirmed standalone catalyst for the day. |
- 1. TMUS-5.57%T-Mobile USWireless telecom carrierFell as a premium-plan push clouded near-term subscriber growth and broadband-repricing fears hit the telecom group.
- 2. DVA-5.56%DaVitaKidney dialysis services providerContinued a multi-session slide on dialysis margin concerns; no fresh standalone catalyst was confirmed for the day.
- 3. PSKY-4.67%Paramount SkydanceMedia, film studios and streamingDropped after Barclays downgraded it to Underweight on streaming-growth challenges, with its Warner deal facing state lawsuits.
- 4. CPRT-3.76%CopartOnline salvage and used-vehicle auctionsSlid with no clear company-specific catalyst; likely rotation out of steadier cyclicals into tech and semiconductors.
- 5. CSGP-3.51%CoStar GroupCommercial real-estate data and online marketplacesFell with no clear standalone catalyst; a rate-sensitive real-estate-data name pressured by the higher-for-longer rate outlook.
- 6. CMCSA-3.46%ComcastCable broadband, media and entertainmentDeclined amid broadband-repricing concerns weighing on cable and media names.
- 7. BLDR-3.30%Builders FirstSourceBuilding materials and construction supplyHit a fresh 52-week low as the Fed's rate hike and higher-for-longer outlook pressured housing-linked names.
- 8. AXON-3.19%Axon EnterpriseTasers, body cameras and public-safety softwareExtended a roughly 15% weekly drawdown as the high-multiple name kept giving back gains, though analysts remain bullish.
- 9. CRM-3.07%SalesforceCloud CRM and enterprise softwareFell to a 19-month low after RBC cut its price target, amid ongoing concerns over AI disruption to enterprise software.
- 10. RDDT-3.03%RedditSocial-media platform and online communitiesSlid with high-multiple software and AI-derivative names; no confirmed standalone catalyst for the day.
Common Themes
The losers split into a few threads: telecom, cable and media hit by broadband-repricing fears (TMUS, CMCSA) and a streaming downgrade (PSKY); rate-sensitive names pressured by the higher-for-longer rate outlook (BLDR at a 52-week low, CSGP); and richly valued software / AI-derivatives giving back gains (CRM at a 19-month low, AXON, RDDT). DVA fell on dialysis margin concerns, while CPRT had no clear standalone catalyst — likely rotation.
Overall read
On a relief rebound after the Fed's surprise hike, money rotated decisively into AI hardware, semiconductors and data-center power, and out of telecom/broadband, rate-sensitive housing and some high-multiple enterprise software. The split shows investors leaning back into the AI-infrastructure trade while shedding rate-sensitive and repricing-exposed defensives.