The S&P U.S. Style Indices completed their annual rebalance in December 2025. Exhibit 1 shows that the 2025 changes were less pronounced than prior years: turnover for the S&P 500^® Growth and S&P 500 Value was lower than the past three annual rebalances. Nonetheless, there were several shifts in index composition.

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The most significant movement was in Information Technology. Post-rebalance, Information Technology companies accounted for nearly half of the S&P 500 Growth, an increase of 7.5% (see Exhibit 2). This gain was driven by the reclassification of some of the largest S&P 500 companies, supported by strong earnings, sales growth and momentum factors. Meanwhile, the weights of Consumer Discretionary, Industrials and Consumer Staples collectively declined by 6.8%.

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Although the post-rebalance Information Technology and Communication Services weights in the S&P 500 Growth rank among the highest since the current S&P U.S. Style Indices’ approach to defining style was introduced in 2009, these levels are not unprecedented. For instance, Information Technology companies accounted for 55.3% of the index in August 2000 (see Exhibit 3). Likewise, Energy’s absence from the S&P 500 Growth after the 2025 reconstitution is not unprecedented—this last occurred in May 2002, following a long-term decline in its weight. Specifically, Energy companies exhibited stronger price-to-book, price-to-earnings and sales-to-price ratios alongside weaker sales and earnings growth. These shifts underscore how the S&P U.S. Style Indices can reflect prevailing market trends, with AI currently serving as a key driver of the U.S. Information Technology and Communication Services sectors, while mostly lower, more volatile commodity prices shaped the reclassification of Energy companies after record profitability in 2021-2022.

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While Financials has traditionally dominated the S&P 500 Value, Information Technology’s growing influence in the U.S. large-cap segment has reshaped the index composition. Since the 2024 rebalance, Information Technology has held the largest sector weight in the S&P 500 Value and maintained that leadership throughout 2025 (see Exhibit 4).

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Although the reclassification of various tech companies contributed to Information Technology’s weight falling by 8.5% at the latest rebalance, the sector continued to be the largest in the S&P 500 Value (see Exhibit 5). Financials was the second-largest sector, and its weight increased at the latest rebalance. Consumer Discretionary’s weight rose by 3.1%, reaching its highest post-rebalance weight in the S&P 500 Value since 2009 and ranking as the third-largest sector at 11.3%. Industrials (up 2.7%) and Consumer Staples (up 2.2%) also saw their weight increase.

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These shifts highlight the growing influence of Information Technology within the S&P 500 and illustrate how sector weights adjust to changes in company fundamentals and market dynamics. While these trends explain much of the rebalance impact, the underlying methodology remains the foundation of the index composition. Understanding these mechanics can offer valuable insight into how growth and value indices evolve over time and may also help with interpreting changes beyond headline numbers.

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