S&P 100 Rebalancing: Sandisk and Dell to Join as Nike Exits

Key Facts

1Sandisk, Dell Technologies, Palo Alto Networks, and Arista Networks will join the S&P 100 index on Monday, Sept. 21.

2Nike is scheduled to leave the S&P 100 index on the same day the new companies are added.

In a move reflecting the shifting market capitalization toward the technology sector, S&P Dow Jones Indices has announced significant changes to the S&P 100 composition. According to reports, Sandisk, Dell Technologies, Palo Alto Networks, and Arista Networks are scheduled to join the index on Monday, Sept. 21. Simultaneously, Nike is set to exit the blue-chip index, highlighting a strategic pivot toward high-growth technology and semiconductor firms.

This rebalancing occurs as tech peers demonstrate significant market weight compared to traditional consumer sectors. Per market data, Sandisk (SNDK) closed at $1,791.82, while Dell Technologies (DELL) stood at $568.06 as of the close on September 18, 2026. In contrast, Nike (NKE) closed at $35.51 on the same date, illustrating the valuation dynamics driving the index provider's decision to refresh its membership list.

Traders should watch for institutional volume shifts when the changes take effect, with Arista Networks (ANET) at $199.39 and Palo Alto Networks (PANW) at $363.58 as of the September 18, 2026 snapshot. While the upcoming economic calendar shows no major catalysts for the immediate implementation date, the primary driver for these instruments will be the structural buying and selling associated with the index inclusion and exclusion.