S&P Dow Jones Indices unveiled a major benchmark overhaul that will add Vertiv and EchoStar to the S&P 500, triggering a 5.6% surge in Vertiv's shares during after-hours trading. The quarterly reshuffle also welcomes Lumentum and Viavi Solutions, while removing GoDaddy, Visteon, Aflac, and NetApp to maintain market-cap balance.

This sweeping change extends beyond the S&P 500, with the S&P 100 seeing semiconductor and industrial leaders like NXP Semiconductors and Rockwell Automation join the blue-chip index. Meanwhile, veteran financial firms Aflac and State Street exit the 100-member club. The adjustments reflect S&P DJI's commitment to keeping indices representative of their respective market-cap ranges.

Investors are bracing for billions in passive fund flows as institutional managers realign portfolios to match the new benchmarks. The changes take effect over the next two weeks, starting with SmallCap 600 adjustments on March 13 and S&P 500 additions on March 23. These moves underscore the growing influence of technology and industrial sectors in shaping market indices.