S&P Dow Jones Indices is expected to announce S&P 500 changes Friday, with Bloom Energy, Astera Labs, Cheniere Energy, and Everpure among the top candidates for the September rebalance, according to Barron’s.
The changes are expected to take effect around Sept. 21, when the quarterly rebalance updates share counts and other index factors.
Index funds must adjust when companies enter or leave the benchmark, creating automatic buying for additions and selling for removals.
Passive money turns index changes into trading events
The S&P 500 is followed by almost $27T in passive assets, with the September reshuffle set to take effect after markets close on Sept. 18, according to CryptoBriefing.
That forced-money dynamic is why additions often rise before they officially join the benchmark.
It also explains why market watchers track the lowest-valued current members as closely as the strongest candidates.
Trade Desk, Builders FirstSource, Norwegian Cruise Line Holdings, Molson Coors, and Mosaic recently had five of the lowest market values in the index.
The S&P 500 has made 11 additions and 11 removals in 2026, with technology and industrials among the most active sectors.
Marvell Technology and Flex joined the benchmark in June, replacing Pool Corp. and Campbell’s Company.
Bloom Energy's momentum rush
Bloom Energy has become a leading candidate after strong earnings, a $61B market value, and a 144% year-to-date stock gain tied to AI power demand, according to MarketWatch.
Bloom also reported sales above $1B, giving the market a simple narrative around data-center electricity needs.
Cheniere has a different case.
It has been eligible for some time, and energy has not had a new S&P 500 addition since 2022.
Astera Labs adds another AI-adjacent option, while Rocket Companies and Affirm Holdings have also appeared on candidate lists.
Rocket was the sixth-largest eligible company and the largest eligible financial stock, while Affirm had a medium probability of joining during the third-quarter rebalance, according to CNBC.
SpaceX will not enter this round because S&P Dow Jones Indices kept its 12-month public-company requirement.
For you, the key risk is chasing the announcement after index funds have already started positioning.
The rebalance can create demand, but it does not replace valuation, earnings quality, or sector risk.