Marvell Technology and Flex Set to Join S&P 500; Others to Join S&P MidCap 400 and S&P SmallCap 600

Rhea-AI Summary

Coeur Mining (NYSE:CDE) will be added to the S&P MidCap 400, effective before the market opens on June 22, 2026, as part of S&P Dow Jones Indices’ quarterly rebalance.

CDE will join the index’s Materials sector, replacing BellRing Brands.

Positive

• Coeur Mining to join S&P MidCap 400 on June 22, 2026
• CDE classified in Materials sector within S&P MidCap 400
• Addition occurs as part of official S&P quarterly index rebalance

Negative

• None.

News Market Reaction – CDE

+3.76%

56 alerts

+3.76% News Effect

-3.8% Trough in 2 hr 5 min

+$634M Valuation Impact

$17.50B Market Cap

0.8x Rel. Volume

On the day this news was published, CDE gained 3.76%, reflecting a moderate positive market reaction. Argus tracked a trough of -3.8% from its starting point during tracking. Our momentum scanner triggered 56 alerts that day, indicating high trading interest and price volatility. This price movement added approximately $634M to the company's valuation, bringing the market cap to $17.50B at that time.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement details multiple S&P index rebalances effective June 22, 2026, with Coeur Mining (...

Analysis

This announcement details multiple S&P index rebalances effective June 22, 2026, with Coeur Mining (CDE) added to the S&P MidCap 400. Historically, CDE’s news flow—covering conferences, a $0.02 semiannual dividend, and major capital actions—has produced both rallies and double-digit declines. Investors may watch how index inclusion interacts with recent buyback activity under the $750 million program, insider sales of 39,000 shares, and prior volatile reactions to otherwise neutral corporate updates.

Key Figures

Effective date: June 22, 2026

1 metrics

Effective date June 22, 2026 Index changes for S&P 500, S&P MidCap 400, S&P SmallCap 600

Historical Context

5 past events · Latest: Jun 04 (Neutral)

Pattern 5 events

Date	Event	Sentiment	24h Move	Catalyst
Jun 04	Conference participation	Neutral	-11.4%	Management participation in RBC Global Mining & Materials Conference.
May 27	Sector commodity update	Positive	-2.9%	Higher silver prices and stronger sector conditions commentary.
May 22	Conference participation	Neutral	+4.2%	CEO participation in Raymond James London Silver Conference.
May 14	Conference participation	Neutral	-9.2%	Executives presenting at Canaccord Global Metals & Mining Conference.
May 13	Dividend announcement	Positive	-1.7%	Declaration of inaugural semi-annual dividend of $0.02 per share.

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

Pattern Detected

Recent news, including conference participation and a new dividend, has often coincided with negative moves, indicating a tendency for the stock to sell off or remain weak even around neutral-to-positive headlines.

Recent Company History

Over the last few months, Coeur Mining has highlighted conference participation on May 20, May 27, and June 11, 2026, plus its inaugural $0.02 semiannual dividend and sector commentary around strong silver prices. Despite these generally neutral-to-positive updates, share reactions have been mixed, with several double-digit declines (e.g., -9.23% on May 14 and -11.42% on June 4). Today’s index rebalancing news adds another corporate milestone against this backdrop of volatile responses.

Key Terms

s&p 500, s&p midcap 400, s&p smallcap 600, gics sector

4 terms

s&p 500 technical

"changes to the S&P 500, S&P MidCap 400, and S&P SmallCap 600 indices effective"

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 midcap 400 technical

"changes to the S&P 500, S&P MidCap 400, and S&P SmallCap 600 indices effective"

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 technical

"changes to the S&P 500, S&P MidCap 400, and S&P SmallCap 600 indices effective"

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 technical

"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 5, 2026 /PRNewswire/ -- S&P Dow Jones Indices will make the following changes to the S&P 500, S&P MidCap 400, and S&P SmallCap 600 indices effective prior to the open of trading on Monday, June 22, 2026, to coincide with the quarterly rebalance. The changes ensure that each index is more representative of its market capitalization range. The companies being removed from S&P MidCap 400 and S&P SmallCap 600 are no longer representative of the mid-cap and small-cap market space, respectively. 

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
June 22, 2026	S&P 500	Addition	Marvell Technology	MRVL	Information Technology
June 22, 2026	S&P 500	Deletion	Pool Corp	POOL	Consumer Discretionary
June 22, 2026	S&P 500	Addition	Flex	FLEX	Information Technology
June 22, 2026	S&P 500	Deletion	The Campbell's Company	CPB	Consumer Staples
June 22, 2026	S&P MidCap 400	Addition	Roku	ROKU	Communication Services
June 22, 2026	S&P MidCap 400	Deletion	Flex	FLEX	Information Technology
June 22, 2026	S&P MidCap 400	Addition	Coeur Mining	CDE	Materials
June 22, 2026	S&P MidCap 400	Deletion	BellRing Brands	BRBR	Consumer Staples
June 22, 2026	S&P MidCap 400	Addition	Semtech	SMTC	Information Technology
June 22, 2026	S&P MidCap 400	Deletion	Coty	COTY	Consumer Staples
June 22, 2026	S&P MidCap 400	Addition	Sanmina	SANM	Information Technology
June 22, 2026	S&P MidCap 400	Deletion	Concentrix	CNXC	Industrials
June 22, 2026	S&P MidCap 400	Addition	Viavi Solutions	VIAV	Information Technology
June 22, 2026	S&P MidCap 400	Deletion	Blackbaud	BLKB	Information Technology
June 22, 2026	S&P SmallCap 600	Addition	Pool	POOL	Consumer Discretionary
June 22, 2026	S&P SmallCap 600	Deletion	Embecta	EMBC	Health Care
June 22, 2026	S&P SmallCap 600	Addition	The Campbell's Company	CPB	Consumer Staples
June 22, 2026	S&P SmallCap 600	Deletion	Universal Health Realty Trust	UHT	Real Estate
June 22, 2026	S&P SmallCap 600	Addition	Coty	COTY	Consumer Staples
June 22, 2026	S&P SmallCap 600	Deletion	Semtech	SMTC	Information Technology
June 22, 2026	S&P SmallCap 600	Addition	Concentrix	CNXC	Industrials
June 22, 2026	S&P SmallCap 600	Deletion	Sanmina	SANM	Information Technology
June 22, 2026	S&P SmallCap 600	Addition	Blackbaud	BLKB	Information Technology
June 22, 2026	S&P SmallCap 600	Deletion	Viavi Solutions	VIAV	Information Technology
June 22, 2026	S&P SmallCap 600	Addition	Credit Acceptance	CACC	Financials
June 22, 2026	S&P SmallCap 600	Deletion	Oxford Industries	OXM	Consumer Discretionary
June 22, 2026	S&P SmallCap 600	Addition	Lazard	LAZ	Financials
June 22, 2026	S&P SmallCap 600	Deletion	Gogo	GOGO	Communication Services
June 22, 2026	S&P SmallCap 600	Addition	Eastern Bankshares	EBC	Financials
June 22, 2026	S&P SmallCap 600	Deletion	PRA Group	PRAA	Financials
June 22, 2026	S&P SmallCap 600	Addition	Wesbanco	WSBC	Financials
June 22, 2026	S&P SmallCap 600	Deletion	Insteel Industries	IIIN	Industrials
June 22, 2026	S&P SmallCap 600	Addition	Warby Parker	WRBY	Consumer Discretionary
June 22, 2026	S&P SmallCap 600	Deletion	Ethan Allen Interiors	ETD	Consumer Discretionary
June 22, 2026	S&P SmallCap 600	Addition	Nicolet Bankshares	NIC	Financials
June 22, 2026	S&P SmallCap 600	Deletion	Cytek Biosciences	CTKB	Health Care
June 22, 2026	S&P SmallCap 600	Addition	Liquidia	LQDA	Health Care
June 22, 2026	S&P SmallCap 600	Deletion	Monro	MNRO	Consumer Discretionary
June 22, 2026	S&P SmallCap 600	Addition	Rush Street Interactive	RSI	Consumer Discretionary
June 22, 2026	S&P SmallCap 600	Deletion	Vital Farms	VITL	Consumer Staples
June 22, 2026	S&P SmallCap 600	Addition	United States Lime & Minerals	USLM	Materials
June 22, 2026	S&P SmallCap 600	Deletion	Cable One	CABO	Communication Services
June 22, 2026	S&P SmallCap 600	Addition	InvenTrust Properties	IVT	Real Estate
June 22, 2026	S&P SmallCap 600	Deletion	Forward Air	FWRD	Industrials

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/marvell-technology-and-flex-set-to-join-sp-500-others-to-join-sp-midcap-400-and-sp-smallcap-600-302793159.html

SOURCE S&P Dow Jones Indices

FAQ

When will Coeur Mining (CDE) be added to the S&P MidCap 400 index?

Coeur Mining will be added to the S&P MidCap 400 before trading opens on June 22, 2026. According to S&P Dow Jones Indices, the change aligns with its quarterly index rebalance to keep market capitalization representation accurate.

Why is Coeur Mining (CDE) being included in the S&P MidCap 400?

Coeur Mining is being included to help keep the S&P MidCap 400 representative of its market capitalization range. According to S&P Dow Jones Indices, such changes occur during the quarterly rebalance to better reflect evolving mid-cap market composition.

Which company will Coeur Mining (CDE) replace in the S&P MidCap 400?

Coeur Mining will replace BellRing Brands in the S&P MidCap 400 index. According to S&P Dow Jones Indices, companies removed from the index are described as no longer representative of the mid-cap market space within the index methodology.

How will Coeur Mining (CDE) be classified within the S&P MidCap 400 index?

Coeur Mining will be classified in the Materials sector within the S&P MidCap 400. According to S&P Dow Jones Indices, the company’s sector classification follows the Global Industry Classification Standard (GICS) used across its equity indices.

Is the Coeur Mining (CDE) index change part of a broader S&P rebalance?

Yes, the Coeur Mining addition is part of a broader S&P 500, MidCap 400, and SmallCap 600 quarterly rebalance. According to S&P Dow Jones Indices, these coordinated changes aim to keep each index aligned with its target market capitalization segment.