The Nasdaq Composite fell 4.5% for the week ended Friday, October 16, 2026, its worst week since June. The S&P 500 lost 1.9%. The Dow gained 0.7%. The index-level split looks like a mild tech wobble. Underneath, it was a hard rotation out of chips and software into staples, healthcare and energy.
How did the major indexes finish the week of October 12-16?
The S&P 500 closed Friday at 7,659.44, down 1.1% on the day and 1.9% on the week. The Nasdaq Composite closed at 26,140.03, down 2.1% Friday and 4.5% for the week. The Dow finished at 52,002.41, up 0.7% on the week. The Russell 2000 closed at 2,721.37, down 3% on the week.
The Dow is the tell. It rose while the Nasdaq dropped 4.5%, a gap of more than five points in five sessions. Defensive, price-weighted names carried it.
What drove the selloff?
Three things landed in the same week, per HDFC Sky's weekly wrap. Worries about borrowing costs for AI data-center builders put the spending pace in doubt. September inflation ran hot: CPI was 3.7% year over year and PPI rose 1.3% on the month. And oil stayed bid, with the same wrap putting WTI at $97.65, up 4.17% on the week.
Friday's own tape matched. On the OpticAlpha industry heat map, semiconductors were down 3.4%, software down 3.5%, internet content down 2.7%, and oil names up 2.9%.
Where did the money go?
Out of AI hardware and software, into things that do not need cheap capital to grow. HDFC Sky's figures for the week put the information technology sector down 6.24% while consumer staples rose 5.53% and healthcare rose 4.38%. The same wrap lists AMD down 9.2%, Broadcom down 7.6% and Microsoft down 7.2%, against gains of 7.0% in Coca-Cola and 5.2% in Eli Lilly. Treat those single-name figures as one source's tally.
One detail does not fit the usual story. The 10-year Treasury yield fell about 26 basis points from the prior week's high to roughly 5.09%, yet growth stocks still sold off. Lower yields did not rescue them. That points to an equity-specific problem, the AI capital spending bill, rather than a pure rates problem.
What does the earnings calendar look like for October 19-23?
Per one earnings calendar, Coca-Cola and GE report Monday before the open. On Tuesday, GM, RTX, 3M and Halliburton report before the open. Netflix reports after the close, with a countdown site listing 4:01 PM ET. Wednesday brings Abbott, Danaher, Thermo Fisher, AT&T and Philip Morris before the open. Thursday brings P&G, Union Pacific, Lockheed Martin, Mastercard and McDonald's.
That calendar also lists Meta, Tesla, IBM and Texas Instruments after the close Wednesday, and Intel after the close Thursday. I could not confirm the Meta, Tesla or Intel dates with a second source, so check each company's investor relations page before planning around them. All times are ET.
What is worth watching in those reports?
After a week where the Philadelphia Semiconductor Index reportedly fell 12%, the guidance language on AI spending matters more than the quarter's EPS beat. A chip or software name that holds its outlook into this tape gets noticed. One that trims it confirms the worry.
The defensive names have their own test. Staples and healthcare just ran 4% to 5% in a week. Reports from Coca-Cola, Abbott, Danaher and P&G show whether that move had earnings behind it or was only a place to hide.
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