The Magnificent Seven Problem

The “Magnificent Seven” (MAG 7) now account for more than 30% of the S&P 500, meaning they play an outsized role in driving the index’s overall performance and volatility. From January through the end of March, the MAG 7 declined by 11%, a drop significantly steeper than that of the rest of the S&P 500 combined. This divergence highlights just how dependent the index has become on a small group of mega-cap companies. When these seven firms struggle, the impact on the broader market is amplified. Conversely, their strong performance can mask weakness across the remaining 493 companies. For investors, this underscores the importance of monitoring company weightings within an index. 

Source: Yahoo Finance, The Business Week Graphic

Notes: MAG 7 data was taken from MAGS ETF. S&P 500 ex-MAG 7 data was taken from XMAG. Data is YTD to 3/31/2026.

This graph was produced by Lucas Juery, CFA, CFPⓇ and is not intended to provide financial advice.