US Close 25 September 2026: S&P 500 +0.51% to 7,743 as Microsoft's Copilot Overhaul Outweighs Cybersecurity Losses
The S&P 500 closed at 7,743.41 on 25 September 2026, up 39.28 points or 0.51%, as MSFT.US gained 3.66% to $516.17 after Microsoft rebuilt Copilot around Home, Code and a new Autopilot agent. ZS.US fell 10.06% to $193.05 after Zscaler named Ross Tackett chief revenue officer from 1 October, and PANW.US, CRWD.US, FTNT.US, OKTA.US and S.US all lost between 2.90% and 6.67% alongside it. WTI crude fell 2.29% to US$92.44 on reported US and Iran talks over a phased Strait of Hormuz reopening, while the 10-year Treasury yield added 2.2 bp to 5.184%.
At a glance
| Index | Close | Change |
|---|---|---|
| S&P 500 | 7,743.41 | +0.51% |
| Nasdaq Composite | 27,068.72 | +0.48% |
| Dow Jones Industrial Average | 51,828.62 | +0.93% |
| Russell 2000 | 2,837.55 | +0.07% |
| VIX | 14.87 | -5.11% |
US 10-year yield 5.184%, up 2.2 bp. US 30-year yield 5.504%, up 4.3 bp. US Dollar Index 101.04, down 0.25%. Gold US$4,320.50 an ounce, up 0.52%.
For the week, the S&P 500 rose 1.21% from its 18 September close of 7,650.50, the Nasdaq Composite 2.06% and the Dow 0.28%, while the Russell 2000 fell 0.80%.
What moved the index
The S&P 500 added 51 bps on 25 September 2026, and the five named drivers below net to about 34 bps of it.
| Driver | Move | Index contribution |
|---|---|---|
| MSFT.US | +3.66% | about +22 bps |
| AAPL.US | +1.53% | about +10 bps |
| Industrials (XLI.US) and financials (XLF.US) | +0.95% and +0.57% | about +15 bps |
| META.US | -3.33% | about -10 bps |
| Cybersecurity (PANW.US, CRWD.US, FTNT.US) | -2.90% to -3.89% | about -3 bps |
MSFT.US closed at $516.17 after Satya Nadella called the rebuilt Copilot "a new OS for work"; its Autopilot agent keeps working inside Microsoft 365 without a user present and enters private preview by the end of September. META.US gave back 3.33% to $751.66 after its gains on the Muse AI agent release. The residual 17 bps came from breadth: 167 of the 250 largest US-listed names by market value closed higher and 83 lower.
Session highlights
Chip and hardware makers took 10 of the 25 largest gains above $2 billion in market value on 25 September 2026.
- DELL.US +5.01% to $562.89, the largest name on the screen, with QCOM.US +3.97% to $201.97 and ADI.US +2.87% to $393.60.
- 5.54% was the ON.US gain to $77.20; MCHP.US added 5.36% to $78.69, TSEM.US 6.07% to $230.47 and CRDO.US 7.65% to $210.97. NVDA.US closed +0.22%, AMD.US +0.22% and MU.US +0.16%.
- AKAM.US +3.20% to $113.94, down from $128.00 premarket, after Anthropic committed $11.6 billion over seven years to Akamai's cloud.
- COST.US +2.93% to $922.76 on its first session after fiscal Q4 net sales rose 11.2% to $93.9 billion and diluted EPS reached $6.75 against a $6.48 consensus.
- JPM.US +1.33% to $343.06 led the financials; MFG.US +4.83%, SMFG.US +4.31% and MUFG.US +4.03% added the Japanese bank ADRs.
- University of Michigan consumer sentiment finished September at 48.1, against a 47.8 preliminary reading and 51.7 in August.
Sector scorecard
Eight of the eleven S&P 500 sectors rose on 25 September 2026, led by industrials at +0.95%.
- XLI.US +0.95%, XLK.US +0.80% and XLF.US +0.57% led the gainers; XLV.US +0.49% and XLP.US +0.44% followed.
- XLC.US -0.90% and XLE.US -0.89% were the weakest, META.US the main communication-services drag and WTI's 2.29% fall the energy input.
- XLRE.US -0.22% was the third decliner. Dispersion from best to worst sector was 1.85 points.
- Technology held the widest internal spread: MSFT.US +3.66% and DELL.US +5.01% against ZS.US -10.06% and PANW.US -3.89%.
Top movers
| Gainer | Change | Close |
|---|---|---|
| PPLI.US | +11.33% | $40.00 |
| ALM.US | +10.65% | $13.72 |
| MXL.US | +10.00% | $93.84 |
| VIAV.US | +9.27% | $40.68 |
| BE.US | +8.27% | $288.70 |
| Loser | Change | Close |
|---|---|---|
| ZS.US | -10.06% | $193.05 |
| FRVO.US | -9.16% | $15.18 |
| PURR.US | -8.80% | $12.85 |
| TWLO.US | -7.96% | $275.80 |
| ACAD.US | -6.76% | $20.68 |
- PPLI.US +11.33% to $40.00 after a Wall Street Journal report that MGM Resorts is weighing a bid for People Inc., two days after People withdrew its $48.30 a share proposal for MGM.
- ALM.US +10.65% to $13.72 as Stifel started coverage at Buy with a $25 target; Goldman Sachs started at Neutral with $13.
- MXL.US, VIAV.US and BE.US rose with the chip and hardware group. No company announcement on any of the three.
- ZS.US -10.06% on the chief revenue officer change, with S.US -6.67%, TENB.US -6.66%, SAIL.US -6.69% and OKTA.US -5.54% following.
- FRVO.US -9.16% to $15.18 after BofA cut its target to $30 from $36, citing a lower peer multiple and a timing shift at Cape Station.
- PURR.US -8.80%. Unannounced, likely flow-driven; bitcoin fell 0.65%.
- TWLO.US -7.96% to $275.80 after HSBC cut Twilio to Reduce, citing the Meta Muse agent.
- ACAD.US -6.76% to $20.68, a second session lower after remlifanserin missed its primary endpoint.
After-hours earnings
COST.US closed 25 September 2026 at $922.76, up 2.93%, in the first full session after its fiscal Q4 report the previous evening.
- COST.US traded at $891.53 premarket, 0.55% below its 24 September close.
- $0.15 of Costco's $6.75 quarterly EPS came from one-off IEEPA tariff refunds.
Next session catalysts (ET)
- Tue 29 Sep, 10:00am: August JOLTS job openings.
- Wed 30 Sep, 8:30am: Q2 GDP revision, corporate profits, and August personal income and outlays, which carries the PCE price index.
- Fri 2 Oct, 8:30am: September employment report.
- 5.184% on the 10-year and 5.504% on the 30-year are the yields going into Monday's session.
- US$92.44 WTI with the US and Iran talks on a phased Strait of Hormuz reopening still open.
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