US stocks had a split week from October 12 to 16, 2026. The S&P 500 fell 1.95% to 7,659.44 and the Nasdaq Composite dropped 4.48% to 26,140.03, both their worst week since June.
The Dow Jones Industrial Average moved the other way, gaining 0.67% to 52,002.41. Heavy selling in technology and chip stocks drove the gap. Inflation, bond yields and oil added to the pressure.
This recap walks through what moved, using closing prices. Weekly changes compare Friday's close with the prior Friday's close.
How the major indexes finished
The table shows where each index closed on Friday, October 16, and how it did over the week.
Index | Close (points) | Week change (%) | Friday change (%) |
|---|---|---|---|
S&P 500 | 7,659.44 | -1.95 | -1.09 |
Nasdaq Composite | 26,140.03 | -4.48 | -2.15 |
Dow Jones Industrial Average | 52,002.41 | +0.67 | -0.34 |
Russell 2000 | 2,721.37 | -3.05 | -1.66 |
The Dow and the Nasdaq finished the week 5.15 percentage points apart. This was a sell-off in one theme, not in the whole market.
The Nasdaq posted its first weekly loss in five weeks. The S&P 500 gave back more than the previous week's gain, when it had set an all-time high. The S&P 500, Nasdaq and Russell 2000 each closed Friday at their lowest level of the week.
Why technology stocks fell
The main driver was worry about how the artificial intelligence buildout is being paid for. CBS News described investor concern over the heavy borrowing tied to building data centers.
Chip stocks took the brunt. The VanEck Semiconductor ETF (SMH) lost about 10% on the week, its biggest weekly drop since April 2025, according to CNBC. The PHLX Semiconductor Index closed lower for an eighth straight session on Friday, per Investrade.
CoreWeave, which rents out computing power to AI developers, fell nearly 12% on Friday and roughly 25% on the week. Several large chip names also dropped on Friday:
AMD: down 6.0%
Intel: down 5.8%
Micron: down 5.6%
Broadcom: down 4.5%
Of the 75 technology stocks in the S&P 500, all but seven closed lower on Friday. The pressure was global: South Korea's Kospi had its worst week since 2008, falling more than 14%, CNBC reported.
Inflation, yields and oil
Inflation came in above forecasts
Consumer prices rose 3.7% in September from a year earlier, reported on Wednesday, October 14. Economists had expected 3.6%. Core prices, which exclude food and energy, rose 2.6% against a forecast of 2.5%.
Gasoline jumped 9.1% in the month and accounted for more than half of the monthly increase. The S&P 500 fell 1.11% that day.
Treasury yields fell anyway
The 10-year Treasury yield topped 5.30% earlier in October, its highest level since 2002. It ended the week near 5.09%, about 15 basis points lower. The Federal Reserve meets next on October 27 and 28.
Oil settled above $100
West Texas Intermediate crude settled Friday at $101.41 a barrel, up 3.51% on the day. Brent crude finished at $109.86. Energy is now a major part of the inflation story, with the CPI energy index up 20.4% from a year ago.
Where investors moved
Money did not leave the market; it rotated. The consumer staples fund XLP rose about 5%, its best week since February, according to Stocktwits. The consumer discretionary fund XLY slipped 0.35%.
Fund | What it tracks | Week change (%) |
|---|---|---|
SPY | S&P 500 | -1.97 |
QQQ | Nasdaq-100 | -5.5 |
XLP | Consumer staples | about +5 |
XLY | Consumer discretionary | -0.35 |
SMH | Semiconductors | about -10 |
The gap between SPY and QQQ shows why concentration matters. Two funds that both hold large US companies finished about 3.5 points apart. If you track simulated portfolios on Odin500, a week like this is a useful check on how much exposure sits in one theme.
Earnings season starts mixed
Third-quarter reports began with the big banks on October 13 and 14.
Goldman Sachs: $17.01 per share, well above forecasts.
JPMorgan Chase: $5.57 per share, below the roughly $5.90 analysts expected.
Wells Fargo: $1.87 per share, ahead of the $1.84 forecast.
Citigroup: profit up 40% from a year earlier.
Analysts expect third-quarter earnings for S&P 500 companies to rise 29.0%, down from 29.4% a week earlier, according to FactSet figures cited by John Hancock Investments.
Key takeaways
The S&P 500 fell 1.95% and the Nasdaq 4.48%, while the Dow rose 0.67%.
Worry about AI financing hit chips hard: SMH lost about 10% and CoreWeave about 25%.
Inflation of 3.7% and oil above $100 did not stop the 10-year yield from falling to about 5.09%.
Consumer staples gained about 5%, which points to a rotation within the market rather than an exit from it.
The Fed meets October 27 and 28, and third-quarter earnings season continues.
This newsletter is for informational and educational purposes only and is not investment advice. Odin500 portfolios are simulated.
Odin500 market data (October 22, 2026)
Figures from Odin500 live market API. As of 2026-10-22.
Key indices & ETFs
| Benchmark | Ticker | 1M | YTD | 6M |
|---|---|---|---|---|
| S&P 500 | SPX | -0.1% | +13.1% | +9.8% |
| Dow Jones | DJI | +1.6% | +9.3% | +7.5% |
| Nasdaq-100 | NDX | -2.2% | +18.3% | +12.6% |
| S&P 500 ETF | SPY | -0.1% | +13.2% | +9.8% |
| Nasdaq-100 ETF | QQQ | -2.2% | +18.3% | +12.6% |
Sector ETFs
| Sector | Ticker | 1M | YTD | 6M |
|---|---|---|---|---|
| Technology (XLK) | XLK | -3.2% | +30.7% | +21.9% |
| Financials (XLF) | XLF | -0.3% | +1.4% | +5.9% |
| Energy (XLE) | XLE | +9.1% | +49.3% | +22.0% |
| Healthcare (XLV) | XLV | +5.9% | +15.1% | +22.6% |
| Industrials (XLI) | XLI | -1.0% | +6.5% | -1.8% |
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