The S&P 500 extended its losing streak to four sessions on September 11, with investors increasingly focused on one figure above all others: WTI crude near $100 a barrel. That oil move, combined with firmer producer inflation and rising Treasury yields, pushed major equity benchmarks lower and revived concern that monetary policy could stay restrictive for longer.
By mid-morning, the S&P 500 was down 46.22 points, or 0.61%, at 7,590.14. The Nasdaq Composite fell 0.71% to 26,067.86, while the Dow Jones Industrial Average lost 294.50 points, or 0.56%, to 52,086.16. Small caps remained under heavier pressure, with the Russell 2000 dropping 0.85% after a weaker open.
The market backdrop has shifted quickly. Volatility rose, bond yields climbed, and leadership narrowed as defensive shares outperformed. For investors, the key question is no longer whether inflation cooled in prior months, but whether higher energy prices are about to reaccelerate inflation into the next Federal Reserve decision.
Key Facts
- The S&P 500 traded at 7,590.14, down 0.61%, marking its fourth consecutive decline.
- WTI crude for October delivery rose $3.30 to $99.35 after touching $100.10 intraday, while Brent climbed to $105.37.
- August producer prices increased 0.4% month over month and 5.4% year over year, up from 4.8% in July.
- The 10-year Treasury yield rose to 4.91%, its highest level since 2023, adding pressure to equity valuations.
- AeroVironment shares gained as much as 11.32% after reporting fiscal Q1 2027 revenue of $480.5 million and record funded backlog of $1.5 billion.
S&P 500
The latest drop in the S&P 500 reflects a market repricing around inflation, interest rates, and economic sensitivity rather than a broad earnings collapse. Oil has become the central variable. With WTI near $100 and Brent above $105, investors are recalculating how quickly higher energy costs could feed into wholesale and consumer inflation, especially after the August producer price index showed annual growth accelerating to 5.4%.
That matters because the rates market is now confronting the possibility that the Federal Reserve may have less flexibility to look through an energy-driven inflation shock. Weekly jobless claims came in at 206,000, essentially in line with expectations, underscoring that the labor market has not weakened enough to offset price concerns. A firm labor backdrop and hotter energy prices create a difficult setup for equities already trading at elevated multiples.
The pressure was especially visible in rate-sensitive areas. The Russell 2000 underperformed again, a sign that smaller companies with higher financing costs and less pricing power are more exposed to rising yields and input inflation. At the same time, sectors with steadier cash flows and lower commodity exposure, including managed care, attracted relative buying interest.
Oil near $100, a 5.4% annual PPI reading, and a 10-year yield at 4.91% have become the three numbers driving risk sentiment across U.S. equities.
Why copper miners sold off while AVAV rallied
One of the sharpest moves on the session came in copper-linked equities. Freeport-McMoRan fell 7.69% to $70.37, Southern Copper dropped 6.49% to $195.68, and Teck Resources lost 7.62% to $64.98. The selling was disproportionate to the move in copper itself, which traded near $6.76 a pound, down only 0.66%.
The decline appears tied to a rapid unwind of tariff-driven positioning after indications that Washington had not decided whether to impose broader tariffs on refined copper. That distinction is important for investors: the long-term supply story for copper has not disappeared, but stocks that had benefited from policy speculation were forced to reprice quickly once confidence in that catalyst faded.
In contrast, AeroVironment stood out as one of the clearest single-stock gainers. The defense technology company reported fiscal Q1 2027 revenue of $480.5 million, beating consensus by $24.5 million, while adjusted EPS of $0.59 came in well ahead of expectations near $0.22 to $0.25. Funded backlog reached a record $1.5 billion, up 37% year over year, supported by a $464.8 million U.S. Army high-energy laser award and additional drone and reconnaissance contracts.
Implications for Investors
For portfolios, the main issue is not simply that stocks are falling. It is why they are falling. A market can usually tolerate weaker growth if bond yields decline at the same time. The current setup is more difficult because equities are facing a combination of higher oil, firmer inflation expectations, and a rising 10-year yield. That mix tends to compress valuation multiples, particularly in growth stocks and small caps.
Investors may want to watch three areas closely over the coming sessions. First is consumer inflation data, which could confirm whether producer-level energy pressure is feeding through more broadly. Second is the Treasury market, where a 10-year yield near 4.91% raises the discount rate used across equities, real estate, and other long-duration assets. Third is sector leadership: continued strength in managed care, defensive communications, and selective defense names would suggest that institutional capital remains in a risk-reduction posture.
There are also pockets of opportunity, but selectivity matters. AeroVironment shows that earnings quality, backlog visibility, and exposure to defense spending can still command a premium even in a weak tape. On the other hand, recent moves in copper miners, retail, and crypto-linked names show how quickly crowded trades can unwind when macro conditions change. Investors should distinguish between businesses facing temporary positioning-driven volatility and those whose fundamentals are genuinely deteriorating.
The next catalyst is likely to come from inflation data and the Federal Reserve response. If oil stays elevated and yields remain near multi-year highs, equity markets may struggle to regain momentum, especially in the most rate-sensitive corners of the market.