Nasdaq falls 4.5% in a week as AI debt fears hit tech, while Brent jumps to $109.86

Wall Street ended the week split in two. Big technology stocks fell hard as investors started asking whether companies borrowing heavily to build AI data centres will earn that money back. Old-economy stocks held up. The Dow actually rose.

Meanwhile, oil jumped to its highest settlement since May, and a hot US inflation report swung bond markets around. All three matter for India on Monday.

The week in US stocks

• Nasdaq Composite26,140.03, down 4.5% for the week and 2.1% on Friday alone.
• S&P 5007,659.44, down 1.9% for the week and 1.1% on Friday.
• Dow Jones52,002.41, up 0.7% for the week despite a 0.3% dip on Friday.
• Russell 20002,721.37 (small companies), down 3.0% for the week.

Even after this week, the S&P 500 is up 11.9% for 2026 and the Nasdaq is up 12.5%, the AP's figures show. So this is a pullback within a strong year, not a collapse.

Why tech fell: AI and debt

The trigger was CoreWeave, a company that rents out AI computing power. It carries about $50 billion of debt, TheStreet reported, and its shares were down nearly 12% at one point on Friday. That sparked a wider sell-off in AI-linked stocks. The S&P 500 technology sector fell more than 3% on Friday, while energy stocks rose 2.52% as oil climbed.

The worry is not that AI is useless. It is about who is paying for it. Companies that fund AI spending from their own profits are being treated differently from those funding it with loans. Capital.com's Daniela Hathorn said upcoming Big Tech earnings "will still need to demonstrate" that the spending pays off. Netflix reports on 20 October, the start of a busy stretch of results.

Inflation and bonds

US consumer prices rose 3.7% in the year to September, above the 3.6% economists expected. Core inflation, which leaves out food and energy, was 2.6%.

Bond markets swung sharply. The 10-year US Treasury yield, which sets the tone for borrowing costs worldwide, went from a peak near 5.33% to a low of 5.05% within about 24 hours, according to Schwab. It was around 5.10% on Friday. If you are new to how yields work, see why bond prices and yields move in opposite directions.

Traders now see a lower chance of a Fed rate hike at its 27–28 October meeting: about 17%, down from roughly 45% before the inflation report, Schwab said. But markets still put the odds of a hike by year-end above 90%. The US dollar index slipped about 0.4% for the week to around 101.6, its first weekly fall after three weeks of gains, Trading Economics reported.

Oil: up again

Brent crude, the global benchmark India tracks, settled at $109.86 a barrel on Friday, up 3.7% on the day and 4.9% for the week. US crude (WTI) gained 10.4% for the week to $101.41. Traders reacted to a missile aimed at Saudi Arabia's Red Sea port of Yanbu, attacks on shipping near the Strait of Hormuz, Ukrainian strikes on a Russian refinery, and a large 8.6 million barrel drop in US crude stocks, EnergyNow reported, citing Reuters settlement data.

Why it matters for India

• Oil billIndia imports most of its crude. Brent near $110 means a bigger import bill, pressure on the rupee and on inflation. See what $100 oil does to India.
• IT stocksIndian IT companies earn much of their revenue in the US. They led the Nifty higher this week on strong results (see Friday's markets update), so a global tech sell-off is something to watch on Monday.
• Foreign moneyUS yields above 5% keep pulling money towards US bonds. Foreign investors sold a net ₹5,285.37 crore of Indian shares on Thursday alone, PTI reported. See how a Fed hike pulls money out of India.
• RupeeA slightly softer dollar has helped. The rupee settled at 95.06 per dollar on Thursday, its fifth straight gain, Business Standard reported. Dealers there expect inflows from the Jio Platforms IPO to support it.

What to watch next week

• Jio Platforms IPOOpens 21 October and closes 23 October, with a price band of ₹1,065 to ₹1,119 and an issue size of up to ₹30,213 crore, Business Today reported. See how an IPO works.
• US earningsNetflix on 20 October, and whether Big Tech can calm worries about AI spending.
• Oil and the GulfAny further attacks on shipping or Gulf ports could push crude higher still.

Educational content only, not investment advice.