📈 Mega-Cap Share of the S&P 500 Holds Near Record Levels at Around 42% - Voronoi
Dec 12, 2025
📈 Mega-Cap Share of the S&P 500 Holds Near Record Levels at Around 42%
From December through November 9, 2025, the combined market capitalization of the ten largest U.S. companies remained close to 42% of the S&P 500—hovering near its record high and underscoring the index’s continued concentration in mega-cap stocks.
