S&P 500 Added Vylor and Selected Twilio

Index changes involve stocks including Vylor and Twilio, which may influence your portfolio exposure.

Updated on Oct. 2, 2026 in Investing

Bold flat-color editorial illustration showing a balance scale weighing structural index blocks, navy and cream colors. — S&P Dow Jones Indices updated its S&P 500 membership to include Vylor and Twilio, triggering automatic portfolio rebalancing for passive index funds. AI Illustration. Upload story photo >

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S&P Dow Jones Indices has updated its index membership, adding Vylor to the S&P 500 while selecting Twilio to replace Warner Bros. Discovery. These adjustments are forcing shifts across multiple index tiers and driving price movement for the affected companies.

Why it matters

Index membership changes affect the composition of funds held in many retirement accounts, as index-tracking investment vehicles must automatically adjust their holdings to match the updated benchmarks. These movements are frequently triggered by corporate acquisitions, such as the upcoming Paramount Skydance deal for Warner Bros. Discovery.

Following the index announcement, Vylor and Twilio shares saw after-hours price gains of 3% and 1.2%, respectively. These changes reflect the immediate demand from index funds that must rebalance their portfolios to mirror the new S&P 500 composition.

The players

S&P Dow Jones Indices

A financial data provider that manages the composition of major stock benchmarks used by millions of index funds.

Twilio

A cloud communications software company now shifting from the MidCap 400 into the S&P 500.

Vylor

A publicly traded company that recently began regular-way trading on the New York Stock Exchange.

Warner Bros. Discovery

A global media and entertainment company exiting the S&P 500 due to its pending acquisition.

Corteva

An agricultural chemical and seed company transitioning from the S&P 500 to the MidCap 400 index.

The details

S&P Dow Jones Indices executes these shifts to maintain index integrity when companies are acquired or undergo major structural changes. When a stock is added to a major index like the S&P 500, passive investment funds are required to purchase the security to maintain their tracking mandate, often creating upward price pressure. As part of this rotation, Corteva is moving to the MidCap 400, while Olin moves to the SmallCap 600, illustrating how single-index updates ripple across secondary markets.

Twilio entered the MidCap 400 in August 2025.
Vylor replaced Corteva in the S&P 500 on October 1, 2026.
Twilio joins the S&P 500 before the market open on October 6, 2026.
Corteva leaves the S&P 500 before the market open on October 6, 2026.

Money Landscape

These index updates follow the standard S&P 500 inclusion and exclusion cycle that occurs when companies are removed due to acquisitions. Such turnover remains a routine part of index management as the underlying market adjusts to structural corporate changes.

If you hold broad-market index funds, these changes will automatically update your underlying asset exposure without requiring any action on your part. Consult with a qualified financial professional to determine if specific index shifts have moved your portfolio outside of your target risk allocation.

The takeaway

While index rebalancing can lead to short-term price volatility for affected stocks, passive investors typically see these shifts handled seamlessly by their fund managers. You may want to periodically review your account statements to understand if major corporate shifts have changed the overall concentration of your index fund holdings.