Allison Transmission Holdings Set to Join S&P MidCap 400 and Goodyear Tire & Rubber to Join S&P SmallCap 600

Rhea-AI Summary

Goodyear Tire & Rubber (NASD: GT) will move from the S&P MidCap 400 to the S&P SmallCap 600 effective before trading on July 6, 2026. Allison Transmission will join the MidCap 400, and Stellar Bancorp will be removed from the SmallCap 600 following its acquisition by Prosperity Bancshares.

Positive

• GT added to S&P SmallCap 600 effective July 6, 2026

Negative

• GT removed from S&P MidCap 400 effective July 6, 2026

News Market Reaction – GT

-2.12%

-2.12% Session close to close

In the Jul 1 session, GT declined 2.12%, reflecting a moderate negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement shifts GT from the S&P MidCap 400 to the S&P SmallCap 600 on July 6, reflecting in...

Analysis

This announcement shifts GT from the S&P MidCap 400 to the S&P SmallCap 600 on July 6, reflecting index rebalancing rather than fundamentals. Recent history shows frequent post-news declines; moderate short interest adds volatility risk to monitor.

Key Figures

Index change effective date: July 6, 2026 Acquisition close expected: July 1

2 metrics

Index change effective date July 6, 2026 Date GT moves from S&P MidCap 400 to S&P SmallCap 600

Acquisition close expected July 1 Prosperity Bancshares acquisition of Stellar Bancorp expected close date

Historical Context

5 past events · Latest: Jun 04 (Neutral)

Pattern 5 events

Date	Event	Sentiment	24h Move	Catalyst
Jun 04	Brand promotion event	Neutral	-2.4%	Goodyear blimp 101st birthday event and marketing-focused celebration in Akron.
Jun 03	Lunar tire contract	Positive	-1.7%	Agreement to supply advanced lunar tires for NASA Artemis Pegasus vehicle.
Jun 01	Debt offering priced	Negative	-1.0%	Pricing of $1.05 billion 8.875% senior unsecured notes due 2032.
Jun 01	Debt offering launch	Negative	-2.3%	Launch of $750 million senior notes offering mainly to refinance 2027 notes.
May 06	Q1 2026 earnings	Negative	-6.0%	Q1 net loss with weak demand, higher raw material costs and rationalization charges.

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

Pattern Detected

GT has often traded lower after a variety of recent news items, including both promotional updates and fundamental announcements.

Key Terms

s&p midcap 400, s&p smallcap 600, gics sector

3 terms

s&p midcap 400 financial

"Allison Transmission Holdings Inc. (NYSE: ALSN) will replace Goodyear Tire & Rubber Co. (NASD: GT) in the S&P MidCap 400"

The S&P MidCap 400 is a group of 400 companies that are smaller than the big, well-known corporations but larger than tiny startups. It helps investors see how medium-sized companies are performing in the stock market, acting like a barometer for this middle-sized group of businesses.

s&p smallcap 600 financial

"Goodyear Tire & Rubber will replace Stellar Bancorp Inc. (NYSE: STEL) in the S&P SmallCap 600"

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

"Effective Date | Index Name | Action | Company Name | 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, June 30, 2026 /PRNewswire/ -- Allison Transmission Holdings Inc. (NYSE: ALSN) will replace Goodyear Tire & Rubber Co. (NASD: GT) in the S&P MidCap 400, and Goodyear Tire & Rubber will replace Stellar Bancorp Inc. (NYSE: STEL) in the S&P SmallCap 600 effective prior to the opening of trading on Monday, July 6. S&P MidCap 400 constituent Prosperity Bancshares Inc. (NYSE: PB) is acquiring Stellar Bancorp in a deal expected to close July 1.

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
July 6, 2026	S&P MidCap 400	Addition		Allison Transmission	ALSN	Industrials
July 6, 2026	S&P MidCap 400	Deletion		Goodyear Tire & Rubber	GT	Consumer Discretionary
July 6, 2026	S&P SmallCap 600	Addition		Goodyear Tire & Rubber	GT	Consumer Discretionary
July 6, 2026	S&P SmallCap 600	Deletion		Stellar Bancorp	STEL	Financials

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View original content:https://www.prnewswire.com/news-releases/allison-transmission-holdings-set-to-join-sp-midcap-400-and-goodyear-tire--rubber-to-join-sp-smallcap-600-302815143.html

SOURCE S&P Dow Jones Indices

FAQ

When will Goodyear Tire & Rubber (GT) join the S&P SmallCap 600 index?

Goodyear Tire & Rubber (GT) will join the S&P SmallCap 600 before the market opens on July 6, 2026. According to S&P Dow Jones Indices, this follows index changes linked to the Stellar Bancorp acquisition.

Why is Goodyear Tire & Rubber (GT) leaving the S&P MidCap 400?

GT is leaving the S&P MidCap 400 as part of scheduled index changes tied to the Stellar Bancorp acquisition by Prosperity Bancshares. According to S&P Dow Jones Indices, Allison Transmission will take GT’s place in the MidCap 400.

Which companies are being added to and removed from S&P indices on July 6, 2026?

On July 6, 2026, Allison Transmission joins the S&P MidCap 400 and GT joins the S&P SmallCap 600. According to S&P Dow Jones Indices, GT and Stellar Bancorp are being removed from the MidCap 400 and SmallCap 600, respectively.

How is the Stellar Bancorp (STEL) acquisition affecting S&P index membership?

Prosperity Bancshares’ acquisition of Stellar Bancorp is prompting index adjustments effective July 6, 2026. According to S&P Dow Jones Indices, Stellar Bancorp will be deleted from the S&P SmallCap 600, while GT moves into that index and Allison Transmission joins the MidCap 400.

What happens to Goodyear Tire & Rubber’s (GT) sector classification after the index change?

GT remains classified in the Consumer Discretionary sector after moving to the S&P SmallCap 600. According to S&P Dow Jones Indices, only its index membership changes on July 6, 2026, not its Global Industry Classification Standard (GICS) sector.