Nasdaq rises 2.3% as Meta and chipmakers lead; oil extends a four-day drop
S&P 500 +1.5% and Nasdaq Composite +2.3% on Monday, September 21, 2026, as Meta and semiconductors led; equal-weight S&P 500 +0.2%; WTI crude -4.4%.
Meta Platforms rose 11.3% on Monday, adding $192 billion of market value after its Muse AI assistant ranked as the top free U.S. app on Apple's and Google's stores. That one holding contributed more to the S&P 500 than any other stock. The index closed up 1.5% at 7,764.22, and the Nasdaq Composite gained 2.3% to 27,122.09. The equal-weight S&P 500 rose 0.2%.
The gap is the session. Cap-weighted technology and communications did the work while energy, staples and utilities went the other way, crude extended a four-day decline, and the 10-year Treasury yield eased after climbing back to 5.01% on Friday. A reader who owned the market through its largest names had a very different Monday from one who owned it evenly.
The S&P 500 beat its equal-weight twin by 1.4 points
The S&P 500 fund SPY rose 1.6%. Invesco's equal-weight S&P 500 fund RSP, which holds the same companies in like size, gained 0.2%, a 1.4 percentage-point gap. The Nasdaq-100 fund QQQ added 2.8%, a fourth straight advance that began on the Federal Reserve's hike day last Wednesday. The Russell 2000 fund IWM rose 0.5% on lighter-than-usual volume and is still down 3.8% over one month. The Dow industrials fund DIA gained 0.8%.
The communications fund XLC rose 3.6% and the technology fund XLK 2.8%, both on their heaviest volume in 20 sessions. The energy fund XLE fell 2.9%; consumer staples and utilities each lost 1.1%.
Communications led Monday; energy was the drag
- +3.6%
- +2.8%
- +1.1%
- +0.4%
- +0.1%
- +0.1%
- +0.05%
- −0.5%
- −1.1%
- −1.1%
- −2.9%
That is the same split as SPY versus RSP: the index climbed because its largest growth names did, and anything tied to oil or the average stock did not. Across the U.S.-listed ETF universe, 4,323 of 5,511 funds closed higher.
Muse, AMD and a one-week chip bounce
Sensor Tower counted more than 900,000 Muse downloads in the six days after Meta introduced the assistant on September 8, more than the 773,000 its predecessor Meta AI app logged over the same post-launch window, and the app held the No. 1 free slot on both major U.S. stores on Monday. Appfigures, using iOS downloads in the United States and Canada, put Muse's first twelve days at 1.8 million against 1.3 million for ChatGPT's early mobile launch. Wells Fargo raised its price target to $796 from $640 before the open.
Meta is a 20% weight in XLC; it contributed 2.31 percentage points of that fund's 3.6% gain. In SPY the same stock, at a 2.2% weight, contributed 0.25 percentage points.
Chipmakers supplied the rest of the leadership. Advanced Micro Devices rose 9.9% to $615.52 and closed with a market value of $1.00 trillion, after trading as high as $616.63, matching its 52-week high. Intel gained 12.1%, Qualcomm 9.3%, and Arm Holdings 17.2%. Nvidia, still the largest holding in SPY, rose a more ordinary 2.3%.
The iShares Semiconductor ETF SOXX, a fund of the 30 largest U.S.-listed chip companies, jumped 4.9%. That extends a rebound from last Monday's 6% slide in semiconductor funds: from that session's close, SOXX is up 12.5% in five days. AMD, Meta, Intel and Nvidia together accounted for 1.24 percentage points of QQQ's 2.8% advance.
Warner Bros. Discovery rose 10.8% after Paramount Skydance settled the state antitrust case over their proposed combination. Paramount's own shares closed down 2.9%.
Crude's fourth down day still leaves oil higher on the month
West Texas Intermediate was at $91.90 a barrel at 4:23 p.m. ET, down 4.4%. Brent was at $99.97, down 3.8%. Reports tied the decline to diplomatic efforts around the U.S.-Iran conflict and a partial recovery in Saudi shipments. The U.S. oil fund USO fell 3.7%, a fourth consecutive decline that also began on September 16, and XLE lost 2.9%, with Exxon Mobil and Chevron the largest weights against it.
That is a sharp one-day move, not a reset. USO is still up 98% over 12 months.
USO is still higher on the month after four down days
Two- and three-times leveraged long energy funds closed lower to a fund, with a median decline of 4.5%.
The Treasury par curve printed a 4.96% 10-year yield and 5.29% on the 30-year. The long-Treasury fund TLT rose 0.7%. Chicago Fed President Austan Goolsbee, speaking in London, restated the awkward constraint the September 16 hike did not remove: if supply shocks persist, "the only way to bring inflation down is to raise rates and narrow the gap between supply and demand."
Equal-weight lagged for a second session
If you own the S&P 500 through SPY, Monday paid 1.6%. If you own the same 500 companies evenly through RSP, it paid 0.2%.
Nasdaq-100 pulled away; equal-weight finished lower
- QQQ · 741.47
- SPY · 773.5
- RSP · 212.7
Frequently asked
Why did Meta jump so much?
Its Muse AI assistant ranked as the top free app on both major U.S. stores, with downloads outpacing its predecessor, and Wells Fargo raised its price target before the open.
Why did the equal-weight S&P 500 barely move?
The gains were concentrated in the largest technology and communications names, while energy, staples and utilities fell, so the average stock added little.
Does the oil drop mean the energy rally is over?
It was a sharp one-day move tied to U.S.-Iran diplomacy and recovering Saudi shipments, but the U.S. oil fund is still higher on the month and up 98% over 12 months.
What happened in chips?
AMD, Intel, Qualcomm and Arm all rose sharply, lifting the iShares Semiconductor ETF 4.9% and extending a rebound from the prior Monday's 6% slide.