Ares Management Set to Join S&P 500; Sezzle and Vital Farms to Join S&P SmallCap 600

S&P Dow Jones Indices announced index rebalances effective prior to the open on Dec 11 and Dec 15, 2025.

Rhea-AI Summary

S&P Dow Jones Indices announced index rebalances effective prior to the open on Dec 11 and Dec 15, 2025. Ares Management (ARES) will join the S&P 500 replacing Kellanova (K) on Dec 11. Vital Farms (VITL) and Sezzle (SEZL) will join the S&P SmallCap 600 on Dec 11 and Dec 15, replacing Heidrick & Struggles (HSII) and Vital Energy (VTLE) respectively. Several deletions follow announced acquisition transactions that are expected to close pending final conditions.

Positive

• Ares Management (ARES) added to S&P 500 on Dec 11, 2025
• Vital Farms (VITL) added to S&P SmallCap 600 on Dec 11, 2025
• Sezzle (SEZL) added to S&P SmallCap 600 on Dec 15, 2025

Negative

• Kellanova (K) removed from S&P 500 on Dec 11, 2025
• Heidrick & Struggles (HSII) removed from S&P SmallCap 600 on Dec 11, 2025
• Vital Energy (VTLE) removed from S&P SmallCap 600 on Dec 15, 2025

Argus Dec 9 session

+0.01% close to close Open Argus

Details

News Market Reaction – K

On Dec 9, the first trading day after this news, K closed 0.01% above the previous close.

Data tracked by StockTitan Argus for the Dec 9 session.

Market Context

This announcement details S&P index changes driven by completed and pending acquisitions, including ...

Analysis

This announcement details S&P index changes driven by completed and pending acquisitions, including Kellanova’s removal from the S&P 500 as Mars takes it private. It follows earlier disclosures of a cash merger at $83.50 per share and subsequent delisting steps. Investors may focus on how index removals, deal closure timing on December 11, 2025, and related SEC filings interact with the stock’s final trading dynamics and remaining arbitrage spread.

Key Figures

Effective date: December 11, 2025 Effective date: December 11, 2025 Effective date: December 15, 2025

Effective date

December 11, 2025

ARES added to S&P 500; K removed

Effective date

December 11, 2025

VITL added; HSII removed from S&P SmallCap 600

Effective date

December 15, 2025

SEZL added; VTLE removed from S&P SmallCap 600

Historical Context

5 past events · Latest: Dec 08

5 events

1. Dec 08

   Acquisition approval

   24h Move

   +0.4%

   Final European approval for Mars acquisition and anticipated Dec 11 closing.

2. Dec 08

   Product launch

   24h Move

   +0.4%

   RXBAR expands into Protein Energy Bites with new high-protein formats.

3. Dec 02

   Brand marketing

   24h Move

   +0.1%

   Pop-Tarts Bowl mascot and TikTok activations to support event sponsorship.

4. Dec 01

   Co-branded product

   24h Move

   -0.7%

   Pop-Tarts flavor collaboration with Keurig’s Original Donut Shop brand.

5. Dec 01

   Tech strategy

   24h Move

   -0.7%

   Overview of CPG tech trends and reported gains from analytics initiatives.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

s&p 500, s&p smallcap 600, gics sector

3 terms

s&p 500 financial

"changes to the S&P 500 and S&P SmallCap 600: Ares Management (NYSE: ARES) will replace"

The S&P 500 is a broad stock market index that tracks the performance of 500 large U.S. companies, weighted so bigger firms have a larger impact. Investors use it like a thermometer or benchmark to judge how the overall U.S. stock market or a portfolio is doing; movements in the index influence investor sentiment, fund performance, and many passive investment products that aim to match its returns.

View in glossary

s&p smallcap 600 financial

"S&P SmallCap 600: Ares Management (NYSE: ARES) will replace Kellanova (NYSE: K)"

A stock market index made up of 600 small-cap U.S. companies chosen to represent the performance of smaller publicly traded firms. It matters to investors because it acts like a temperature gauge for the small-company segment of the market, serving as a benchmark for fund managers, a basis for index funds and ETFs, and a way to compare returns and risk when building a diversified portfolio.

gics sector financial

"Ticker | GICS Sector"

GICS sector is one of the major industry groupings from the Global Industry Classification Standard, a system that sorts companies into consistent categories (like Technology or Health Care) based on the primary business they do. Investors use these sectors like folders in a filing cabinet to compare companies, build diversified portfolios, and track how whole parts of the market are performing rather than focusing on single stocks.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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NEW YORK, Dec. 8, 2025 /PRNewswire/ -- S&P Dow Jones Indices will make the following changes to the S&P 500 and S&P SmallCap 600: 

• Ares Management (NYSE: ARES) will replace Kellanova (NYSE: K) in the S&P 500 effective prior to the open of trading on Thursday, December 11. Mars Inc. is acquiring Kellanova in a deal expected to close soon, pending final closing conditions.
• Vital Farms Inc. (NASD: VITL) will replace Heidrick & Struggles Intl Inc. (NASD: HSII) in the S&P SmallCap 600 effective prior to the opening of trading on Thursday, December 11. Advent International and Corvex Private Equity are acquiring Heidrick & Struggles Intl in a deal expected to be completed soon, pending final closing conditions.
• Sezzle Inc. (NASD: SEZL) will replace Vital Energy Inc. (NYSE: VTLE) in the S&P SmallCap 600 effective prior to the opening of trading on Monday, December 15. S&P SmallCap 600 constituent Crescent Energy Co. (NYSE: CRGY) is acquiring Vital Energy in a deal expected to close soon, pending final closing conditions.

Following is a summary of the changes that will take place prior to the open of trading on the effective date:

Effective Date	Index Name		Action	Company Name	Ticker	GICS Sector
Dec 11, 2025	S&P 500	Addition		Ares Management	ARES	Financials
Dec 11, 2025	S&P 500	Deletion		Kellanova	K	Consumer Staples
Dec 11, 2025	S&P SmallCap 600	Addition		Vital Farms	VITL	Consumer Staples
Dec 11, 2025	S&P SmallCap 600	Deletion		Heidrick & Struggles Intl	HSII	Industrials
Dec 15, 2025	S&P SmallCap 600	Addition		Sezzle	SEZL	Financials
Dec 15, 2025	S&P SmallCap 600	Deletion		Vital Energy	VTLE	Energy

ABOUT S&P DOW JONES INDICES

S&P Dow Jones Indices is the largest global resource for essential index-based concepts, data and research, and home to iconic financial market indicators, such as the S&P 500® and the Dow Jones Industrial Average®. More assets are invested in products based on our indices than products based on indices from any other provider in the world. Since Charles Dow invented the first index in 1884, S&P DJI has been innovating and developing indices across the spectrum of asset classes helping to define the way investors measure and trade the markets.

S&P Dow Jones Indices is a division of S&P Global (NYSE: SPGI), which provides essential intelligence for individuals, companies, and governments to make decisions with confidence. For more information, visit www.spglobal.com/spdji/en/. 

FOR MORE INFORMATION:

S&P Dow Jones Indices
index_services@spglobal.com

Media Inquiries
spdji.comms@spglobal.com

View original content:https://www.prnewswire.com/news-releases/ares-management-set-to-join-sp-500-sezzle-and-vital-farms-to-join-sp-smallcap-600-302635867.html

SOURCE S&P Dow Jones Indices

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

When does Ares Management (ARES) join the S&P 500 and which company does it replace?

Ares Management (ARES) joins the S&P 500 prior to the open on Dec 11, 2025, replacing Kellanova (K). According to S&P Dow Jones Indices, the change is effective before trading opens on Dec 11, 2025, tied to a corporate acquisition of Kellanova.

Why is Kellanova (K) being removed from the S&P 500 on Dec 11, 2025?

Kellanova (K) is removed because it is being acquired, prompting the index deletion on Dec 11, 2025. According to S&P Dow Jones Indices, the removal follows the announced Mars Inc. acquisition, which is expected to close pending final conditions.

Which companies join the S&P SmallCap 600 on Dec 11 and Dec 15, 2025?

Vital Farms (VITL) joins on Dec 11, 2025 and Sezzle (SEZL) joins on Dec 15, 2025. According to S&P Dow Jones Indices, those additions replace Heidrick & Struggles (HSII) and Vital Energy (VTLE), respectively.

Will the index changes affect trading dates for ARES, VITL, SEZL in December 2025?

The changes take effect prior to the open on Dec 11 and Dec 15, 2025, impacting index inclusion from those trading days. According to S&P Dow Jones Indices, additions and deletions are effective before market open on the stated dates.

Are the deletions of HSII and VTLE from the S&P SmallCap 600 related to acquisitions?

Yes; Heidrick & Struggles (HSII) and Vital Energy (VTLE) are deleted amid announced acquisition transactions expected to close soon. According to S&P Dow Jones Indices, both deletions are tied to pending deals subject to final closing conditions.