Gulfport Energy and Mobility Global Set to Join S&P SmallCap 600

Core Laboratories (NYSE: CLB) will be removed from the S&P SmallCap 600 prior to the open on July 2, 2026, and replaced by Mobility Global (NYSE: MBGL).

Rhea-AI Summary

Core Laboratories (NYSE: CLB) will be removed from the S&P SmallCap 600 prior to the open on July 2, 2026, and replaced by Mobility Global (NYSE: MBGL).

According to S&P Dow Jones Indices, Core Laboratories is no longer representative of the small-cap market space.

Positive

• None.

Negative

• Core Laboratories (CLB) deleted from S&P SmallCap 600 on July 2, 2026

Argus Jun 29 session

+1.92% close to close Open Argus

Details

News Market Reaction – GPOR

In the Jun 29 session, GPOR gained 1.92%, reflecting a mild positive market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement adds GPOR to the S&P SmallCap 600, potentially broadening its investor base. Past ...

Analysis

This announcement adds GPOR to the S&P SmallCap 600, potentially broadening its investor base. Past news flow has produced volatile reactions, while short interest remains relatively low, so investors may watch how index‑related flows intersect with governance and earnings updates.

Key Figures

Index addition date: July 1, 2026 Index change date: July 2, 2026

Index addition date

July 1, 2026

GPOR added to S&P SmallCap 600, replacing Select Medical Holdings

Index change date

July 2, 2026

Mobility Global joins S&P SmallCap 600; Core Laboratories deleted

Historical Context

5 past events · Latest: May 05

5 events

1. May 05

   CEO appointment

   24h Move

   -7.6%

   Named Domenic J. Dell’Osso Jr. as new President and CEO.

2. May 05

   Q1 2026 earnings

   24h Move

   -7.6%

   Reported Q1 2026 production, cash flow, net income and buybacks.

3. Apr 21

   Earnings schedule

   24h Move

   +1.6%

   Announced timing of Q1 2026 earnings release and conference call.

4. Mar 09

   CEO departure

   24h Move

   -6.8%

   CEO John Reinhart departed and Office of the Chairman was formed.

5. Feb 24

   FY 2025 results

   24h Move

   +1.7%

   Reported strong 2025 results and issued 2026 operational guidance.

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

Key Terms

s&p smallcap 600, gics sector, s&p 500, dow jones industrial average

4 terms

s&p smallcap 600 financial

"Gulfport Energy Corp. (NYSE: GPOR) will replace Select Medical Holdings Corp. (NYSE: SEM) effective prior to the opening of trading on Wednesday, July 1."

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.

s&p 500 financial

"S&P 500 constituent S&P Global Inc. (NYSE: SPGI) is spinning off Mobility Global"

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

dow jones industrial average financial

"home to iconic financial market indicators, such as the S&P 500® and the Dow Jones Industrial Average®."

A stock market index that tracks the share prices of a small group of large, well-known companies to give a quick snapshot of how the broader market is doing. Think of it like a thermometer for the stock market: it uses a handful of heavyweight firms as representative samples to show whether investor sentiment is rising or falling, which helps investors gauge market trends and compare performance over time.

View in glossary

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

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NEW YORK, June 26, 2026 /PRNewswire/ -- S&P Dow Jones Indices will make the following changes to the S&P SmallCap 600:

• Gulfport Energy Corp. (NYSE: GPOR) will replace Select Medical Holdings Corp. (NYSE: SEM) effective prior to the opening of trading on Wednesday, July 1.  Select Medical Holdings is being acquired in a deal expected to be completed soon, pending final closing conditions.
  
  
• Mobility Global Inc. (NYSE: MBGL) will replace Core Laboratories Inc. (NYSE: CLB) effective prior to the opening of trading on Thursday, July 2. S&P 500 constituent S&P Global Inc. (NYSE: SPGI) is spinning off Mobility Global in a transaction expected to be completed July 1. Core Laboratories is no longer representative of the small-cap market space.

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 1, 2026	S&P SmallCap 600	Addition	Gulfport Energy	GPOR	Energy
July 1, 2026	S&P SmallCap 600	Deletion	Select Medical Holdings	SEM	Health Care
July 2, 2026	S&P SmallCap 600	Addition	Mobility Global	MBGL	Industrials
July 2, 2026	S&P SmallCap 600	Deletion	Core Laboratories	CLB	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/gulfport-energy-and-mobility-global-set-to-join-sp-smallcap-600-302812407.html

SOURCE S&P Dow Jones Indices

FAQ

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

When will Core Laboratories (NYSE: CLB) be removed from the S&P SmallCap 600 index?

Core Laboratories is set to be removed from the S&P SmallCap 600 before trading opens on July 2, 2026. According to S&P Dow Jones Indices, this change follows a scheduled index rebalancing that also adds Mobility Global to the index.

Why is Core Laboratories (CLB) being deleted from the S&P SmallCap 600?

Core Laboratories is being deleted because it is described as no longer representative of the small-cap market space. According to S&P Dow Jones Indices, this adjustment is part of index maintenance to keep the S&P SmallCap 600 aligned with its small-cap exposure objective.

Which company will replace Core Laboratories (CLB) in the S&P SmallCap 600?

Mobility Global (NYSE: MBGL) will replace Core Laboratories in the S&P SmallCap 600. According to S&P Dow Jones Indices, MBGL will be added to the index prior to the opening of trading on July 2, 2026, when CLB is simultaneously deleted.

How could the S&P SmallCap 600 deletion affect Core Laboratories (CLB) shareholders?

Deletion from the S&P SmallCap 600 can reduce automatic index-fund ownership of Core Laboratories shares. According to S&P Dow Jones Indices, CLB will be removed July 2, 2026, which may influence trading volumes and demand from small-cap index and ETF investors.

What other index changes are happening when Core Laboratories (CLB) leaves the S&P SmallCap 600?

Alongside Core Laboratories’ removal on July 2, 2026, Mobility Global will be added to the S&P SmallCap 600. According to S&P Dow Jones Indices, Gulfport Energy will also join the index on July 1, replacing Select Medical Holdings, which is being acquired.