it's not important to know how they save their Bitcoin, because even if you know it, it doesn't affect anything in your life or the value of your asset if used the same way with them. Maybe it will increase your doubt to keep hold of your asset if you know they saved it in exchange and felt they were on guard if the market does not meet their expectations.
Trusting third parties is always risky. Think why Satoshi Nakamoto made Bitcoin? To have our own banks with private keys for our bitcoins.
Using third party services, trusting them means we no longer control our private keys and bitcoins.
Good Bitcoin wallets must be non custodial (we own private keys), open source (we can reproduce their wallet and test it or Bitcoin experts can test it through reproducible process).
So, if I were you, I would believe in myself, and not use the wrong way the same with the institutional. Because they have a business target, and must take action immediately to sell their asset if the market crashes suddenly. So if they keep their asset on a non-custody wallet, or with the multi-signature way which is quite complicated to take action
I agree. Using a good Bitcoin wallet, set it up by ourselves and have our own banks.
Verify wallet software before using.
Making wallet backups before using it to store bitcoins.