Marvell and Flex replace Pool Corp. and Campbell’s in June 22 S&P 500 shuffle

Two semiconductor and manufacturing firms just got a timing-and-demand boost. Marvell Technology Inc. and Flex Ltd. will join the S&P 500 before the start of trading on June 22, replacing Pool Corp. and The Campbell’s Company, S&P Dow Jones Indices said Friday.

This is not a “nice to have” headline. Inclusion in the S&P 500 changes the buying behavior of passive index funds that track the benchmark. Those funds must realign their holdings as the index composition changes, meaning that being added can bring forced demand, while being removed can pressure the stock as shares get sold to match the new lineup.

So why these two, now? Start with Marvell. In its latest earnings, Marvell delivered a quarterly forecast that exceeded estimates and boosted its outlook for the year. Fortune’s source ties that improvement to demand for chips used in AI data centers. Put plainly: more AI training and inference is driving more spending on computer systems in data centers, and Marvell is positioned in the chip supply chain for those environments.

Flex’s story is more about guidance and corporate restructuring. The company issued profit guidance for 2027 that exceeded consensus estimates. At the same time, Flex announced it will spin off its cloud and power infrastructure segment. Together, those two items create a classic index-timing cocktail: investors get a signal that the company expects stronger profit performance ahead, while the corporate actions suggest a clearer strategic focus and potentially different market framing going forward.

Behind the scenes, S&P Dow Jones Indices also spelled out the qualification bar. Companies must have a market capitalization of at least $22.7 billion and meet profitability, liquidity and share-float requirements to qualify for the S&P 500 under April guidelines. That matters because the S&P 500 is not just a popularity contest. It is a rules-based gate that determines whether trillions of dollars of benchmarked assets will mechanically add a company to their portfolios.

And S&P’s gatekeeping has become a bigger deal this year because markets are now seeing mega-sized companies before they have much time in public markets. Just on Thursday, S&P Dow Jones Indices said it will keep its existing eligibility requirements for benchmarks, closing the door to fast entry for big tech IPOs like SpaceX.

The index provider also said it will not shorten the 12-month seasoning period for giant newly public companies or waive existing profitability and public-float requirements based on a company’s size. Fortune’s source notes that this diverges from a broader industry shift embraced by rivals Nasdaq Inc. and FTSE Russell. The strategic consequence is blunt: some companies, even extremely large ones, cannot immediately access one of the most reliable sources of demand in modern markets, the stock index that dominates passive allocation.

That is where the stakes get real for executives and boards, not just traders. Quicker inclusion for a mega IPO would have meant forced passive buying. Fortune’s source cites Bloomberg Intelligence estimates suggesting that faster index access would have led to about $14 billion in forced passive buying for SpaceX, more than $8 billion for OpenAI and about $4.6 billion for Anthropic PBC. In other words, the index rules are not academic. They can change how much incremental capital is pulled into a stock on a schedule.

Back to Marvell and Flex: the market reacted immediately. Shares in Marvell rose 6% in after-hours trade and Flex was up 2% following the news. That jump is consistent with what index inclusion typically triggers: investors front-run the idea that passive funds will have to buy as the S&P 500 changes, not just re-rate a company on fundamentals.

Finally, this rebalance also reinforces a broader rhythm on Wall Street. In March, Vertiv Holdings Co., Lumentum Holdings Inc., Coherent Corp. and EchoStar Corp. were added to the index, replacing Match Group Inc., Molina Healthcare Inc., Lamb Weston Holdings Inc. and Paycom Software Inc. The same pattern repeats: companies enter and exit as their fundamentals, growth outlook, and qualification status line up with the index provider’s framework. For any company in similar conversations with the market, this is the lesson: S&P 500 inclusion can be a demand catalyst on top of the fundamental story. Exclusion can do the opposite. And the index gatekeeper is not speeding up just because capital markets move faster now.