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![finnyhal Avatar](https://lunarcrush.com/gi/w:24/cr:twitter::101259374.png) A.adam [@finnyhal](/creator/twitter/finnyhal) on x XXX followers
Created: 2025-07-25 20:36:33 UTC

The S&P is market-cap weighted, meaning the higher a stock climbs, the more ETF funds must buy creating a self-reinforcing loop of overexposure.

🔍 Not Just S&P Even Other Indexes Are Overconcentrated
For example, the Russell 1000 Growth Index is now more concentrated in its top XX companies than the S&P XXX is in its top 25!

And in 2024:

S&P XXX (cap-weighted) returned +15%

S&P XXX Equal-Weight returned +6%
Conclusion? A few big names are doing all the heavy lifting.


X engagements

![Engagements Line Chart](https://lunarcrush.com/gi/w:600/p:tweet::1948844843037589576/c:line.svg)

**Related Topics**
[fund manager](/topic/fund-manager)
[marketcap](/topic/marketcap)
[rating agency](/topic/rating-agency)
[$spy](/topic/$spy)

[Post Link](https://x.com/finnyhal/status/1948844843037589576)