Group 1 - The core point of the article is that FTSE Russell has announced an annual restructuring of the Russell US Index, effective after the market close on June 27, with plans to increase the adjustment frequency from once a year to twice a year starting in 2026 [1][6]. Group 2 - The restructuring will occur in three phases, with the first phase confirming the constituents based on market capitalization after the close on April 30. May and June will serve as transition months, with preliminary adjustment lists communicated to the market starting May 23 and updates provided on May 30, June 6, June 13, and June 20 [3][5]. - The Russell US Index comprises the Russell 1000 Index, which includes the largest 1,000 companies by market capitalization, accounting for 93% of the total investable US equity market, and the Russell 2000 Index, which includes the smallest 2,000 companies [3][5]. - The adjustments to the index have significant market implications, as approximately $10.5 trillion tracks the Russell US-related indices, making the restructuring day one of the largest trading volume days in the US market [5]. Group 3 - The changes are intended to ensure that the Russell US Index remains representative of the market, as market conditions and valuations evolve over time [6]. - On the 2024 adjustment day, the Nasdaq's closing cross-match system executed approximately 2.9 billion shares valued at $95.3 billion in just 0.878 seconds, setting a new record for Russell index restructuring days [5].

Core Viewpoint - Starting from 2026, the adjustment frequency of the Russell US Index will change from once a year to twice a year to better reflect market conditions and valuations [1][6]. Group 1: Adjustment Process - The Russell US Index consists of the Russell 1000, Russell 2000, and Russell 3000 indices. The Russell 1000 includes the largest 1,000 companies by market capitalization, representing 93% of the total investable US stock market, while the Russell 2000 includes the smallest 2,000 companies [3]. - The adjustment process will occur in three phases: the confirmation of index constituents based on market capitalization after the market close on April 30, followed by transitional months in May and June, with preliminary adjustment lists communicated to the market starting May 23 [3][2]. Group 2: Market Impact - The adjustments to the Russell US Index have significant implications for the market, as approximately $10.5 trillion tracks these indices, making adjustment days some of the highest trading volume days of the year [5]. - On the Nasdaq exchange, during the 2024 adjustment day, approximately 2.9 billion shares were traded in just 0.878 seconds, totaling $95.3 billion, setting a new historical record for Russell index rebalancing days [5].