Stocks Slide as 10-Year Hits 5%, Brent Holds Near $108

The U.S. 10-year Treasury yield breached 5% on Monday morning for the first time since 2023, according to Yahoo Finance's live market coverage. Stocks fell with it, as Brent crude sat near $108 a barrel after Saudi Arabia shut a pipeline that bypasses the Strait of Hormuz, and chip shares slid after the chief executives of Anthropic and OpenAI spent the weekend calling for the AI industry to slow down.

Three pressures hit the market at the same time

The clearest single event happened away from the exchange floor. Axios reported on Sept. 12 that Anthropic CEO Dario Amodei published an essay calling for an immediate slowdown in the pace of AI development, warning of potentially devastating consequences within months, and that OpenAI CEO Sam Altman quickly agreed the industry needs to slow frontier-model advances and do more on safety. Axios described Amodei's essay as cautioning that swarms of rogue AI agents could take over the internet in as little as six months.

Bloomberg reported that semiconductor shares came under heavy pressure from the U.S. to Europe and Asia on Monday, with Nvidia and Broadcom slumping and a key industry gauge sinking 5.7%. Yahoo Finance's live blog recorded Samsung down 4.05% in Seoul, and Bloomberg reported the dollar rose the most since June.

The oil leg is separate and older. CNBC reported on Sept. 13 that Brent traded 3.51% higher at $108.28 a barrel and U.S. West Texas Intermediate rose 3.46% to $103.51 as of 4:56 a.m. ET, after drones launched from Iraq damaged Saudi Arabia's East-West pipeline on Thursday and the Saudi government closed it. CNBC put the line's capacity at 7 million barrels per day and said it had been central to easing the supply disruption caused by the Iran war. CNBC also reported that a diplomatic meeting between Iran and Gulf Arab states on the Hormuz situation was postponed after the attack.

The figures, and why the index percentages do not match

Every equity number below is an intraday snapshot, not a closing price, taken at different moments by different publishers.

The disagreement is worth stating plainly. Yahoo Finance's blog, updated at 11:09 a.m. ET, showed the Dow down 0.3% and the S&P 500 down 0.6%, and reported the tech index down 0.8% led by chip losses; Bloomberg reported the Nasdaq 100 down 1.3%. Yahoo's post also labels the ticker ^IXIC, which is the Nasdaq Composite, as the Nasdaq 100, so the index being quoted is ambiguous in that snapshot. Treat both as mid-session readings of a falling market rather than a settled figure for the day. The same applies to crude: Yahoo's quote board showed the October WTI contract at $102.49, up 2.44%, on Monday, while CNBC's $108.28 is Brent on Sunday. Different benchmarks, different contracts, different times.

What a $108 barrel and a 5% 10-year mean two days before a Fed decision

The 5% figure is the yield on the 10-year Treasury note, the rate the U.S. government pays to borrow for a decade. It is not a savings rate or a short-term Treasury bill yield, and it is not what a bank will pay a depositor. It matters to equity investors because it is the discount rate applied to distant profits, which is why Bloomberg tied the move in yields to the pressure on high-multiple technology shares.

The oil and rate stories are connected through inflation, and Bloomberg framed Brent above $108 as raising concern about inflationary pressure ahead of the Fed's decision this week. That connection is a reported explanation, not a proven causal chain: prices in several markets moved on the same morning, which does not by itself establish that any one of them caused the others.

Context the day's headline leaves out: the market did not fall in a straight line into this. Zacks, published via Yahoo Finance, reported that Friday, Sept. 11 was an up session, with the Nasdaq Composite adding 251.31 points, or 1%, to 26,333.04 and the S&P 500 gaining 65.28 points, or 0.9%, to 7,657, helped by an inflation reading without a major upside surprise and retreating oil. Over that full week, however, Zacks reported the Dow fell 1.6%, the S&P 500 0.8% and the Nasdaq 0.7%. Monday's decline therefore extends a weekly loss rather than interrupting a rally.

What remains unknown is specific. CNBC reported no indication of when the East-West pipeline resumes, and the postponed Iran-Gulf meeting on a Hormuz shipping corridor had no replacement date in the coverage reviewed. There is also no evidence in these reports that either AI company has changed a product schedule or capital-spending plan; what has been published is an essay and an expression of agreement, not a disclosed cut to chip orders. Any claim that chip demand will fall is, at this point, an inference from share prices rather than from company guidance.

The dated catalyst: Wednesday's decision and dot plot

The Federal Open Market Committee meets Sept. 15-16, 2026, with the policy statement and rate decision due Wednesday, Sept. 16 at 2:00 p.m. ET alongside the Summary of Economic Projections and dot plot, per published FOMC schedule trackers verified against the Fed's calendar. Market-implied probabilities for that decision circulated before the weekend, but those are dated, model-based estimates derived from futures pricing, not commitments by the committee, and they were calculated before Brent's jump above $108 and the move in the 10-year. The projections will have been finalized during a week in which oil rose sharply, so the committee's own inflation view, not just the rate, is the number to read.