CRH, Vertiv Holdings, Alnylam Pharmaceuticals and Ares Management are top candidates for admission to the S&P 500 when the benchmark index undergoes a quarterly rebalancing this month. Any additions likely will be announced late Friday.

Those four companies, culled from a list drawn up by KBW analyst Shreyank Gandhi, are among the largest not in the S&P 500. S&P Dow Jones Indices, which oversees the index, often taps such corporations for additions.

Other possible additions are Carvana, Ferguson Enterprises, Cheniere Energy, Coupang and Strategy based on their lofty market values. Another potential addition is SoFi Technologies, according to Gandhi.

The S&P 500 index is rebalanced each quarter and that action is often accompanied by additions and deletions. There have been index changes at every rebalancing except one since the start of 2023. The only period without a change was the second quarter of this year.

At the September rebalancing, three new companies were added to the index: Robinhood Markets, AppLovin and Emcor. Robinhood and AppLovin at the time were among the largest companies not in the S&P 500 while Emcor migrated from the S&P mid-cap index to the S&P 500.

What’s the case for some of the largest companies in the list?

CRH is the largest of the group by market value at about $80 billion and is a top provider of construction aggregates and cement. Ares is a leading alternative asset manager and a major player in private credit. Other alt managers like Blackstone and KKR have been added to the S&P 500 index in recent years. Vertiv is a hot maker of cooling systems for data centers and Carvana is a top used-car dealer that nearly folded a few years ago. Alnylam is a successful and innovative biotechnology company.

Memory chip maker SanDisk was recently added to the S&P 500, graduating from the S&P small-cap index after a quadrupling in its stock price since a spinoff in early 2025 from Western Digital.

The minimum market value for new additions to the S&P 500 index is $22.7 billion. S&P Dow Jones Indices says little about why certain companies make it into the S&P 500 and reasons for those not making the cut assuming they meet index criteria.

The admission committee looks at market value and other factors, including profitability and sector representation. Companies with market capitalizations of over $50 billion to $75 billion often make into the S&P 500 although it can take time.

Many companies make their case publicly for admission because of the prestige attached to the S&P 500 and the lift to stock prices from index inclusion. The S&P 500 is the ultimate corporate club.

While possessing a $50 billion market value, Strategy could have a hard time getting added to the S&P 500. One issue is that Strategy is more of a Bitcoin repository than an operating company with ongoing earnings. The company’s software business is small. (S&P Dow Jones Indices doesn’t allow closed-end funds and ETFs into the index.)

While Coupang is eligible due to a Delaware domicile, it’s probably a long shot since most of its business is in South Korea.

Companies with the smallest market values in the S&P 500 are vulnerable to getting demoted to the S&P mid-cap index or even the small-cap benchmark.

The smallest members of the S&P 500 index now include Mohawk Industries, LKQ and Molina Healthcare.

The quarterly rebalancing adjusts the weightings of the S&P 500 components based on changes in their shares outstanding from quarter to quarter. Buybacks, for instance, reduce shares outstanding and a company’s weighting in the index.