Week in Review: S&P 500 Falls 2.4% as Tech Sell-Off Hits Memory Chips

The S&P 500 closed the week down 2.40%, the Nasdaq Composite fell 3.37%, and the Dow Jones Industrial Average slipped 0.94%, each measured against the prior Friday's close. Smaller-company shares also lost ground, with the Russell 2000 down 2.05%, while the volatility index (VIX) jumped 31.84% as the 10-year Treasury yield eased to 4.860%.

Sectors

Communication services led all sectors this week, gaining 4.89%, followed by consumer discretionary at +1.91% and real estate at +1.90%. Financials and consumer staples also finished higher, up 1.15% and 0.74%.

Energy was the week's weakest sector by a wide margin, down 11.97%, with technology close behind at -8.23%. Industrials fell 2.81%, materials dropped 1.52%, and utilities and health care were roughly flat, down 0.69% and 0.02% respectively.

CNBC reported that a broad technology sell-off spread through the week, with memory chipmaker Kioxia Holdings and electronics supplier Renesas Electronics among the decliners, and contract chipmaker TSMC sliding sharply in Taiwan trading. CNBC also noted that Japan's Nikkei 225 entered a bear market, falling more than 20% from its June peak as chip-related shares dragged the index lower.

The week's biggest movers

AppLovin Corporation led S&P 500 gainers this week, up 71.21% to $391.22, followed by Fiserv, up 25.71%, and Idexx Laboratories, up 22.65%. Mosaic Company and Airbnb also posted double-digit weekly gains.

On the losing side, Lumentum Holdings fell 35.94% to $538.59, the steepest decline in the index, followed by Seagate Technology, down 28.48%, and Marvell Technology, down 28.11%. Western Digital and Sandisk rounded out the week's biggest decliners, both falling more than 27%.

Reuters reported that data storage and chip-related names came under pressure after UBS strategists wrote in a note that a slowdown in data center construction could put roughly 30% of expected 2028 capacity additions at risk, a comment the outlet described as weighing on semiconductor and artificial intelligence infrastructure shares. Reuters also reported that utilities and equipment suppliers tied to the data center buildout, including GE Vernova and Constellation Energy, traded lower during the week, while AI server maker Dell also declined.

Earnings and filings

145 companies in the S&P 500 reported quarterly results this week, with 123 beating earnings per share (EPS) estimates, 18 missing, and 3 matching expectations exactly. Apple Inc. was the largest company to report, posting EPS of $2.05 against an estimate of $1.99, a beat.

Other large reporters that beat estimates included Advanced Micro Devices, Palantir Technologies, Amgen, Arista Networks, McDonald's, Qualcomm, Pfizer, ConocoPhillips, and Uber. Separately, 22 stock trade disclosures by members of Congress reached us this week.