*Update at 5:30 p.m. ET: The S&P 500 added Vertiv (VRT), Lumentum (LITE), and Coherent (COHR) in addition to EchoStar (SATS). Match Group, Molina Healthcare, Lamb Weston, and Paycom were deleted. It’s a massive endorsement of AI stocks. We listed Lumentum as a dark horse earlier; it’s now in the index.
We have a full story on the new inclusions here.*
Tonight, after the market closes, S&P 500 index changes for the first quarter of 2026 are expected to be announced. Index funds must buy any newly added stocks, which typically drives significant price appreciation for additions, making this one of the most closely watched calendar events for traders and long-term investors alike. Three names generating the most buzz heading into the announcement: Vertiv (VRT), SoFi Technologies (SOFI), and Lumentum (LITE).
Let’s dive into why each stock could make sense, and which stock prediction markets believe will be added.
Polymarket Puts Vertiv in the Lead
Prediction markets are already pricing in a frontrunner. On Polymarket, bettors give Vertiv a 71% probability of being added to the S&P 500 by March 31, 2026. By comparison, SoFi sits at just 24.5%. Lumentum has no active prediction market on the platform, suggesting the crowd sees it as a longer shot. Prediction markets aren’t guarantees, but they aggregate real money and real conviction. Right now, that conviction is squarely behind Vertiv.
Joining the S&P 500 doesn’t guarantee a stock will jump the following day, but that’s often been the case.
- In September 2025, AppLovin joined the index and shares jumped 11.6%. Robinhood shares were also added and saw a 15.8% jump. However, a third edition Emcor (EME) saw a slight decline the next day.
- Workday joined in December 2024 and saw a 9% jump afterward.
Vertiv: The Polymarket Favorite
It’s not hard to see why. Vertiv is a favorite. The company has become an essential part of the data center buildout and has expertise in high-growth areas like liquid cooling.
Vetiv’s stock is trading at $248.96 today, up an astonishing 53.7% year to date and up 203.88% over the past year.
Its market cap sits at approximately $95.6 billion, well above the S&P 500’s minimum threshold. Recent performance backs the story: Q4 2025 revenue came in at $2.88 billion, up 22.7% year over year, with organic orders surging 252% YoY and a backlog of $15.0 billion. For 2026, management guided for net sales of $13.25 billion to $13.75 billion and adjusted EPS of $5.97 to $6.07.
This is a profitable, high-growth company at the center of the AI infrastructure buildout. It checks the boxes the S&P committee looks for with a market cap well above the $20.5 billion threshold, and is becoming a critical company that represents the AI buildout, which is increasingly driving GDP growth.
We recommended Vertiv in November in our AI Investor Portfolio, and shares have already jumped 45%.
SoFi: The Profitable Underdog
SoFi’s case is more nuanced. The digital bank crossed a milestone in Q4 2025, posting its first-ever $1 billion-plus revenue quarter at $1.025 billion, with 13.7 million members, up 35% year over year. It’s now consistently profitable.
But the stock has struggled in 2026. Shares are at $19.16, down 26.82% year to date, though they are up 53.89% over the past year. Its market cap is approximately $24.5 billion, which clears the S&P 500’s minimum threshold but leaves less margin for comfort than Vertiv. The YTD slide and the more mixed analyst sentiment (more holds and sells than buys) make SoFi a credible but less certain candidate tonight.
Lumentum: The Dark Horse
Lumentum has had one of the most remarkable runs in the entire market. Shares are at $583.00, up 58.17% year to date and up 854.33% over the past year. The company makes optical circuit switches and co-packaged optics, products that are becoming essential plumbing for AI-scale data centers.
Our recommendation on Lumentum, made on November 8, 2024, is now up a staggering 580%!
Its most recent quarter showed revenue of $665.5 million, up 65.5% year over year, with forward guidance of $780 million to $830 million, representing more than 85% year-over-year growth. Its market cap is approximately $46.5 billion, smaller than Vertiv but still substantial.
And yet, the S&P committee will likely want to wait a longer before adding Lumentum. Stocks that join and then drop rapidly are a ‘black eye’ to the index. Lumentum has very solid business fundamentals, but could also drop sharply if market volatility rachets up.
What to Watch
Whatever is announced after the close tonight will move markets. Stocks added to the S&P 500 face immediate, forced buying from index funds that track the benchmark, and that mechanical demand can push prices sharply higher in short order. All three of these companies have earned their way into the conversation. Vertiv is the crowd favorite, SoFi is the profitable wildcard, and Lumentum is the high-momentum dark horse. Watch for the official announcement tonight and the opening prints Monday morning.
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