I think it’s more of the old Bitcoin investors back from 2010 that now own $100M or more in Bitcoin,than new institutional investors for the following reasons;
TLDR;
It's very easy to say so but many people who knew of Bitcoin, invested money in Bitcoin or simply bought a lottery ticket in Bitcoin many years ago, did not become millionaire or billionaire. They either lost their bitcoin by lack of careful wallet backup plans or belief in Bitcoin with price above $1,000 or $10,000 or $20,000. People who did not lost their bitcoin by lack of wallet backups, probably sold their bitcoins with very cheap price like few cents or couple of dollars.
With Bitcoin price in 2025 above $100,000, chances for the poor with limited investment capital to become millionaire or billionaire with Bitcoin investment is very small, and almost impossible.
Fortunately, if they choose Bitcoin for their investment portfolio, they will have an asset that provides them safety and very good chance of getting profit after one market cycle. If they can hold their bitcoin for more than one market cycle, ROI can be considerably better.
Yearly candles and ROIs over years show how good Bitcoin has been as an investment asset.
https://charts.bitbo.io/yearly-candles/https://casebitcoin.com/