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.
Hardware wallets, but that's just only part of it. The big part is that they segment their savings in numerous wallets to keep them as safe as possible. I think everyone learned from that one guy who threw away his hard drive with like a ton of BTC on it and then wanted to obtain a permit from the government to go look for it on a waste dump site XD. Not everyone can afford multiple wallets, but that's the best option.