Closing Summary

U.S. stocks closed broadly lower on Monday, September 28, 2026, as a risk-off tone took hold across both rate-sensitive and growth-heavy corners of the market. The session was shaped by two overlapping pressures: resurgent U.S.-Iran tensions that pushed crude oil and Treasury yields higher, and renewed anxiety around artificial-intelligence safety and spending that weighed on software and high-multiple tech.

Energy and health care were the rare beneficiaries, while communication services and consumer discretionary led the decline. The VIX jumped sharply, signaling that investors were paying up for protection rather than leaning into the dip. With yields back near multi-year highs, the market's tolerance for expensive growth narratives narrowed noticeably by the close.

Indexes

The Dow Jones Industrial Average fell 0.67% to 51,481.51.

The S&P 500 Index fell 0.76% to 7,684.50.

The Nasdaq Composite declined 0.92% to 26,820.38.

The VIX rose to 16.06, +8.00% on the day, its largest one-day jump in recent sessions.

Turnover was elevated: SPY, the S&P 500 tracking ETF, printed roughly 40.8 million shares, while QQQ, the Nasdaq 100 tracker, saw about 30.1 million shares change hands. Figures are as of Monday's 4:00 p.m. ET close.

Stock & Sector Performance

The decline was broad but uneven. Communication services and consumer discretionary were the weakest sectors, while defensive and energy-linked groups held up.

• Worst: XLC (communication services) -1.57%, XLY (consumer discretionary) -1.41%, XLF (financials) -1.17%, XLI (industrials) -0.97%, XLK (technology) -0.88%.
• Best: XLE (energy) +0.11%, XLV (health care) +0.32%, XLP (consumer staples) +0.28%.

Magnificent Seven: the group finished mixed, with Nvidia the lone clear outperformer. AAPL -0.78%, MSFT -1.35%, GOOGL -0.34%, AMZN -1.41%, NVDA +1.68%, META -4.79%, TSLA -3.94%. Nvidia's resilience stood out against a weaker software complex, reflecting continued investor preference for the AI infrastructure layer over application-layer names.

Notable single-stock moves outside the mega-caps: MongoDB fell 18.29% after its CEO's sudden departure, the largest drag among high-profile technology names. Zscaler dropped 10.06% and Twilio fell 7.96%, extending pressure on software and cloud names. On the upside, People Inc. gained 11.33%, Almonty Industries 10.65%, and MaxLinear 10.00%, though these moves were idiosyncratic rather than sector-wide.

Major Company News

The single most market-moving company story of the session was MongoDB's CEO departure, which erased more than 18% of the database software maker's value and underscored how unforgiving the market currently is toward execution risk in AI-adjacent software. Separately, Meta Platforms' continued slide over AI infrastructure spending weighed on communication services; the social-media company's latest quarterly update left investors uneasy about the pace of AI capital outlays relative to monetization visibility, and the stock closed down 4.79%.