US Market Wrap 14 September: Chipmakers Sink on AI Slowdown Calls as the 10 Year Touches 5 Percent
The Nasdaq Composite fell 0.56 percent to close at 26,186.41 on Monday, the S&P 500 0.48 percent to 7,619.98 and the Dow Jones Industrial Average 152.09 points, or 0.29 percent, to 52,421.20, after the leaders of Anthropic, OpenAI and xAI warned of risks from rapid artificial intelligence development, per Reuters, and the selling concentrated in the chipmakers that carry the buildout: the Philadelphia semiconductor index tumbled 5.9 percent, cutting its gain for 2026 to 57 percent, per the same report. The benchmark 10 year Treasury yield briefly rose above 5 percent for the first time since 2023 before the Federal Reserve’s meeting on Wednesday, at which traders price a 90 percent probability of a quarter point rise, per the same report, and on the official par curve the 10 year finished at 4.97 percent, up 1 basis point, on our calculation from the daily readings. The Nasdaq 100 lost 0.82 percent to 29,127.16, the Russell 2000 fell 0.40 percent to 2,892.24 and the Cboe Volatility Index rose 7.95 percent to 17.10. Brent crude settled 1.0 percent higher at 105.68 dollars a barrel as worries about energy supplies mounted after new strikes on Saudi energy infrastructure and attacks on ships in the Middle East, per the same report.
The AI trade splits: chips sink while cybersecurity and software rally
The day’s selling had an address. On Saturday Anthropic chief executive Dario Amodei wrote that “We must slow the pace at which we improve the capabilities of AI models,” and Sam Altman of OpenAI and Elon Musk both said they agree, per CNBC, which reported that Micron Technology, Intel, Marvell Technology and Applied Materials each dropped more than 4 percent, Nvidia fell about 3 percent, Hewlett Packard Enterprise slid about 8 percent, Dell Technologies and Oracle lost roughly 4 percent each and CoreWeave 5 percent, with SK Hynix down 7 percent in US trading. 6 chip stocks had already shed about 360 billion dollars in market value before the open, per our report of 14 September. The same story lifted the other side of the sector: Palo Alto Networks and CrowdStrike, the 2 security leaders, jumped 14 and 15 percent on CNBC’s figures, and they are the vendors tasked with protecting companies and government agencies against attacks built with AI. ServiceNow, Adobe and Workday rallied between 4 and 7.4 percent after selling off in recent sessions on worries that competition from AI companies could squeeze their margins, per Reuters. The board shows where the selling sat: 8 of the 11 S&P 500 sectors fell, 4 of them by more than 1 percent with information technology’s 1.67 percent the board’s worst, while the 3 risers were communication services with 2.79 percent, health care with 1.35 percent and consumer staples with 1.27 percent. Even so, advancing stocks outnumbered falling ones inside the S&P 500 by 1.3 to 1 on the wire’s count, and Bank of America tumbled 5.1 percent after chief executive Brian Moynihan said he expects investment banking fees to fall by at least 10 percent in the third quarter, per the wire’s report.
The 10 year touches 5 percent into the Fed
The rates move ran alongside the equity story. The 10 year’s brief move above 5 percent was its first since 2023, and analysts quoted in the wire’s report called the level a threshold that could ripple through the economy and dent the relative appeal of equities; Jake Dollarhide of Longbow Asset Management said it may pressure the Fed to do more than a single rise. On the Treasury’s official par curve the rise was concentrated in the short and intermediate maturities: the 2 year added 2 basis points to 4.65 percent, the 3 year 4 basis points to 4.73 percent and the 5 year 2 basis points to 4.80 percent, while the 10 year added 1 basis point to 4.97 percent and the 30 year eased 1 basis point to 5.34 percent, on our calculation from the daily readings. On our reading the derating is running through the multiple: the recent decline, set against a strong earnings outlook, leaves the S&P 500 at 19 times expected earnings, its cheapest since April 2025, per the same report. The dollar index rose 0.38 percent to 99.497, the yen weakened 0.55 percent to 154.39 per dollar and bitcoin rose 2.73 percent to 79,341.00 dollars, all at our 20:27 GMT capture on the vendor’s daily basis.
| Index | Close | Change |
|---|---|---|
| Dow Jones Industrial Average | 52,421.20 | -0.29% |
| Russell 2000 | 2,892.24 | -0.40% |
| S&P 500 | 7,619.98 | -0.48% |
| Nasdaq Composite | 26,186.41 | -0.56% |
| Nasdaq 100 | 29,127.16 | -0.82% |
Closes of Monday 14 September 2026 from the vendor’s feed captured at 20:27 GMT, ranked by change; changes are against our published 11 September closes.
| S&P 500 sector | Change |
|---|---|
| Communication services | +2.79% |
| Health care | +1.35% |
| Consumer staples | +1.27% |
| Financials | -0.35% |
| Consumer discretionary | -0.48% |
| Real estate | -0.78% |
S&P 500 sector indices, closes of 14 September 2026 from the vendor’s feed captured at 20:27 GMT, day on day, ranked by change; split across 2 tables for legibility on a phone.
| S&P 500 sector | Change |
|---|---|
| Energy | -0.86% |
| Materials | -1.03% |
| Utilities | -1.34% |
| Industrials | -1.44% |
| Information technology | -1.67% |
Same basis, ranked continuously with the first sector table.
| Maturity | 14 Sep | 11 Sep | Change |
|---|---|---|---|
| 2 year | 4.65% | 4.63% | +2bp |
| 3 year | 4.73% | 4.69% | +4bp |
| 5 year | 4.80% | 4.78% | +2bp |
| 10 year | 4.97% | 4.96% | +1bp |
| 30 year | 5.34% | 5.35% | -1bp |
The official daily par yield curve for 14 and 11 September 2026, read at 20:31 GMT; the Treasury derives the curve from indicative bid side quotations at about 19:30 GMT in US summer time, and the changes are ours. Omitted maturities on 14 September: 1 month 3.94 percent, 3 month 4.11, 6 month 4.18, 1 year 4.37, 7 year 4.88 and 20 year 5.37.
| Instrument | Level | Change |
|---|---|---|
| Cboe Volatility Index | 17.10 | +7.95% |
| Bitcoin, dollars | 79,341.00 | +2.73% |
| US Dollar Index (DXY) | 99.497 | +0.38% |
Intraday quotes captured at 20:27 GMT, ranked by change; the VIX row is the session’s last print on the vendor’s feed, and every change in this table and its note is on the vendor’s daily basis. Ether (2,595.20 dollars, up 3.59 percent), dollar/yen (154.39, up 0.55 percent) and euro/dollar (1.1546, down 0.45 percent) are omitted to keep the table lean.
Why it matters: The selling was an allocation, not an exit, on our reading. The index fell 0.48 percent while advancing stocks outnumbered falling ones inside it by 1.3 to 1 on the wire’s count, the bid went to health care and consumer staples at the defensive end and to communication services, the day’s biggest riser, and even inside technology the same headline that sank the chipmakers lifted the 2 security leaders by 14 and 15 percent, so the market spent Monday repricing who wins from a slower buildout. The S&P 500 has now fallen in 5 of the past 6 sessions on our count, and the second force is rates: the 10 year touched 5 percent for the first time since 2023 with a rate rise 90 percent priced for Wednesday, so the AI pace question and the funds rate are pressing on the same long duration trade at once.
Outlook: The Federal Reserve decides on Wednesday, with traders at 90 percent for a quarter point rise, per the wire’s report, to a 3.75 to 4.00 percent range and with further tightening signalled, per our commodities wrap of 14 September. The same day brings the weekly petroleum status report back to its usual slot, per our Week Ahead of 12 September, which also carries Saudi Arabia’s August consumer and wholesale prices and China’s August activity data on Tuesday, and the Bank of Japan follows on 17 and 18 September, per our US wrap of 11 September. For equities the near test is whether the 10 year holds below 5 percent once the decision is in; for the AI complex it is whether the slowdown talk shows up in capital spending guidance. Brent’s standing test is unchanged from our commodities wrap: a settlement above 107.63 dollars would mean the shipping talks relief has been fully unwound, and Monday finished 1.95 dollars short.
Sources: Reuters, CNBC, US Department of the Treasury, The Edge.
