The decade-by-decade top-10 chart (Lance Roberts, 08/2026) carries two ideas at once. Turnover: of 1990’s top ten (Exxon, GE, IBM, AT&T, Cigna, Altria…), essentially only the oil majors and Microsoft-to-be survived later panels; GE went from #1 to gone; today’s list (Nvidia, Google, Apple, Microsoft, Amazon, Broadcom, Tesla, Meta, Micron, Eli Lilly) would have been mostly unguessable in 2005. Buying today’s giants is a bet that this list is the exception that stays. The churn runs in real time: Tesla, on that very panel, is −38% from its Dec-2025 high, ~$500B of market cap gone (Barchart, 07/2026).
Concentration: the same chart shows the top 10 at ~38% of S&P 500 market cap — far above 2000’s ~25% and 1990’s ~21%. So the cap-weighted index is more exposed to the churn than at any prior panel: if the historical turnover rate holds, the index owns tomorrow’s faders at record weight. The two readings compound each other — which is the argument for Capital rotates, it doesn't leave mattering more now, and the concentration counterpoint to Now show Japan‘s defense of index buy-and-hold.