Sandisk Set to Join S&P 500; Upwork, First Interstate BancSystem, PTC Therapeutics to Join S&P SmallCap 600

Rhea-AI Summary

Gildan (NYSE: GIL) and several companies will move between S&P indices effective late November–early December 2025. Sandisk (SNDK) is being added to the S&P 500 on November 28, 2025, with PTC Therapeutics (PTCT) joining the S&P SmallCap 600 the same day. Upwork (UPWK) and First Interstate BancSystem (FIBK) also join the SmallCap 600 on November 28 and December 2, 2025, respectively; Interpublic, Premier and Hanesbrands will be removed.

Positive

• Sandisk added to S&P 500 on November 28, 2025
• PTC Therapeutics added to S&P SmallCap 600 on November 28, 2025
• Upwork added to S&P SmallCap 600 on November 28, 2025
• First Interstate BancSystem added to S&P SmallCap 600 on December 2, 2025

Negative

• Interpublic deleted from S&P 500 on November 28, 2025
• Hanesbrands deleted from S&P SmallCap 600 on December 2, 2025
• Premier deleted from S&P SmallCap 600 on November 28, 2025

Key Figures

Effective date changes: November 28, 2025 Second effective date: December 02, 2025 Premier deal close: November 25, 2025 +5 more

8 metrics

Effective date changes November 28, 2025 Index additions/deletions for S&P 500 and S&P SmallCap 600

Second effective date December 02, 2025 Additional S&P SmallCap 600 index changes

Premier deal close November 25, 2025 Expected completion date of Premier acquisition

Hanesbrands deal close December 1, 2025 Expected completion date of Hanesbrands acquisition

IPG price change -1.96% 24h move prior to index removal announcement context

IPG 52-week high $33.05 Pre-merger trading range upper bound

IPG 52-week low $22.5101 Pre-merger trading range lower bound

Relative volume 7.7 Today’s volume vs 20-day average for IPG

Market Reality Check

Price: $24.57 Vol: Volume 81,181,037 is elev...

high vol

$24.57 Last Close

Volume Volume 81,181,037 is elevated vs 20-day average 10,544,561 (relative volume 7.7). high

Technical Trading at $24.57, about 25.66% below 52-week high $33.05 and 9.15% above 52-week low $22.5101; price is below 200-day MA at $25.56.

Peers on Argus

IPG is down 1.96% while key peers WPP, QMMM, MGNI, OMC and TTD show gains betwee...

IPG is down 1.96% while key peers WPP, QMMM, MGNI, OMC and TTD show gains between 2.22% and 19.44%, indicating stock-specific trading tied to the merger and index deletion rather than a sector-wide move.

Historical Context

5 past events · Latest: Nov 25 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Nov 25	Certification milestone	Positive	-2.5%	Primis achieved IAB Tech Lab Open Measurement Web Video certification again.
Nov 24	Merger clearance	Positive	-0.0%	EU granted unconditional antitrust approval for Omnicom’s acquisition of IPG.
Nov 20	Research release	Positive	-0.6%	IPG and Momentum released shopper research on in‑store media effectiveness.
Nov 12	Corporate initiative	Positive	-1.5%	Momentum announced Make it Matter Day focused on AI literacy and innovation.
Oct 30	Merger financing step	Positive	-0.2%	Omnicom extended exchange offers for IPG notes tied to expected merger closing.

Pattern Detected

Recent IPG headlines, including merger-related developments and operational updates, were generally constructive but were followed by modestly negative price reactions, suggesting a pattern of selling into news.

Recent Company History

Over the last few months, IPG news has centered on Omnicom’s planned acquisition and operational initiatives. A Nov 20, 2025 research release on in‑store media and the Nov 25, 2025 Primis certification highlighted business capabilities. Merger-related steps, including exchange offer extensions on Oct 30, 2025 and European Commission clearance on Nov 24, 2025, moved the transaction toward closing. Despite largely positive or neutral developments, IPG’s shares showed small negative moves after each event, consistent with today’s index-removal announcement ahead of the completed merger.

Market Pulse Summary

This announcement reflects index housekeeping as Sandisk and several other names are moved between t...

Analysis

This announcement reflects index housekeeping as Sandisk and several other names are moved between the S&P 500 and S&P SmallCap 600 in response to pending acquisitions, including IPG’s sale to Omnicom. For IPG, trading below its 200‑day MA at $25.56 and about 25.66% under its 52‑week high of $33.05, the context includes recent merger clearances and exchange offers. Investors may watch closing logistics, remaining regulatory filings, and any further updates from Omnicom.

Key Terms

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

3 terms

s&p 500 financial

"Sandisk Corp. (NASD: SNDK) will replace The Interpublic Group of Companies Inc. (NYSE: IPG) in the S&P 500"

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.

s&p smallcap 600 financial

"Upwork Inc. (NASD: UPWK) will replace Premier Inc. (NASD: PINC) 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. Not financial advice.

NEW YORK, Nov. 24, 2025 /PRNewswire/ -- S&P Dow Jones Indices will make the following changes to the S&P 500, S&P SmallCap 600: 

• S&P SmallCap 600 constituent Sandisk Corp. (NASD: SNDK) will replace The Interpublic Group of Companies Inc. (NYSE: IPG) in the S&P 500, and PTC Therapeutics Inc. (NASD: PTCT) will replace Sandisk in the S&P SmallCap 600 effective prior to the opening of trading on Friday, November 28. S&P 500 constituent Omnicom Group Inc. (NYSE: OMC) is acquiring The Interpublic Group of Companies in a deal expected to close soon, pending final conditions.
  
  
• Upwork Inc. (NASD: UPWK) will replace Premier Inc. (NASD: PINC) in the S&P SmallCap 600 effective prior to the open of trading on Friday, November 28. Patient Square Capital is acquiring Premier in a deal expected to be completed November 25, pending final closing conditions.
  
  
• First Interstate BancSystem Inc. (NASD: FIBK) will replace Hanesbrands Inc. (NYSE: HBI) in the S&P SmallCap 600 effective prior to the opening of trading on Tuesday, December 2. Gildan Activewear (TMX/NYSE: GIL) is acquiring Hanesbrands in a deal expected to be completed December 1, 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
November 28, 2025	S&P 500	Addition	Sandisk	SNDK	Information Technology
November 28, 2025	S&P 500	Deletion	Interpublic Group	IPG	Communication Services
November 28, 2025	S&P SmallCap 600	Addition	Upwork	UPWK	Industrials
November 28, 2025	S&P SmallCap 600	Addition	PTC Therapeutics	PTCT	Health Care
November 28, 2025	S&P SmallCap 600	Deletion	Sandisk	SNDK	Information Technology
November 28, 2025	S&P SmallCap 600	Deletion	Premier	PINC	Health Care
December 02, 2025	S&P SmallCap 600	Addition	First Interstate BancSystem	FIBK	Financials
December 02, 2025	S&P SmallCap 600	Deletion	Hanesbrands	HBI	Consumer Discretionary

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
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View original content:https://www.prnewswire.com/news-releases/sandisk-set-to-join-sp-500-upwork-first-interstate-bancsystem-ptc-therapeutics-to-join-sp-smallcap-600-302625036.html

SOURCE S&P Dow Jones Indices

FAQ

When will Sandisk (SNDK) join the S&P 500 and what is the effective date?

Sandisk (SNDK) will join the S&P 500 effective prior to the open on November 28, 2025. According to S&P Dow Jones Indices, the change is scheduled to occur before trading begins on that date.

Which companies are being added to the S&P SmallCap 600 on November 28, 2025?

Upwork (UPWK) and PTC Therapeutics (PTCT) will be added to the S&P SmallCap 600 on November 28, 2025. According to S&P Dow Jones Indices, both additions occur effective prior to the open of trading.

Why is Interpublic (IPG) being removed from the S&P 500 on November 28, 2025?

Interpublic (IPG) is being removed because it is being acquired by Omnicom, with the deal expected to close soon. According to S&P Dow Jones Indices, the pending acquisition triggers the index deletion.

When will First Interstate BancSystem (FIBK) join the S&P SmallCap 600 and why?

First Interstate BancSystem (FIBK) will join the S&P SmallCap 600 effective prior to the open on December 2, 2025. According to S&P Dow Jones Indices, the addition follows index rebalancing tied to recent corporate changes.

What happens to Hanesbrands (HBI) in the S&P SmallCap 600 after Gildan's acquisition?

Hanesbrands (HBI) will be deleted from the S&P SmallCap 600 effective December 2, 2025. According to S&P Dow Jones Indices, Gildan's expected acquisition and related corporate changes lead to the removal.