Do they use cold wallets for it like everyone else? If so, do they keep everything in one wallet or do they split the bitcoin into several different wallets?
Let's say 1/3 in Trezor, 1/3 in Ledger, 1/3 in BitBox02? I'm currently trying to transfer my bitcoin from an exchange to a cold wallet for the first time, but I'm wondering if it's safe to keep everything in one wallet from one company.
Every whale has its own way of protecting its bitcoins and we will never know its plans. Maybe they can explain what the plan is but not with details because it's their secret.
But if I were a whale and had, let's say 1000 BTC that I just made from trading, I would split it into pieces.
I'll be using 1/3 on Trezor, 1/3 on Ledger, 1/3 on Bitcoin Core, and a few small pieces in the wallet I have on my phone. And the rest of the rest I will keep in my trading account to trade again and try to make more BTC.
The way you use it is fine to keep everything in one wallet if that makes you comfortable. But if not, you can divide it into several parts. It's all about convenience in storing all your BTC; you need to find it yourself.