By George Glover

Marvell Technology and Flex were rising on Monday as investors reacted to the news that both stocks are set to join the S&P 500 later this month.

Shares in Marvell jumped 7.4% to $283 ahead of the opening bell. Flex rose 3.9% to $157.88. Futures tracking the S&P 500 were 0.2% higher as the market shrugged off an exchange of fire between Iran and Israel.

S&P Dow Jones Indices said in a press release after Friday's close that chip maker Marvell and electronics manufacturer Flex would join the S&P 500 on June 22 as part of a quarterly rebalancing.

The timing could have been better. Marvell slumped 17% and Flex dropped 4.8% at the end of last week as investors slammed the brakes on the artificial-intelligence rally following so-so revenue guidance from Broadcom and a stronger-than-expected May jobs report.

Joining the S&P 500 tends to boost a stock because passive index funds that track the benchmark gauge are legally required to load up on members' shares.

Marvell stock was already up 210% for the year through Friday's close, powered higher by the AI boom driving up demand for the company's chips and networking products.

Flex shares have jumped 151% in 2026, boosted by the surge in construction of data centers.

The two stocks will replace canned foods maker Campbell's and swimming pool supplier Pool in the S&P 500. Campbell's slid 0.8% and Pool declined 0.3% in Monday's premarket.

Write to George Glover at george.glover@dowjones.com

This content was created by Barron's, which is operated by Dow Jones & Co. Barron's is published independently from Dow Jones Newswires and The Wall Street Journal.

(END) Dow Jones Newswires

June 08, 2026 06:30 ET (10:30 GMT)

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