They hold majority of the BTC in cold wallet address. wetsuit had posted their cold storage address in 2017 (see here), but they have moved Bitcoin from that address on the August month of the same year. They were using a different address to keep users Bitcoin after that.

TheQuin had posted another address which has been widely used by Freebitco team as hot wallet. But they have stopped using that address too. I'm not sure whether they are using any address as 'hot wallet address' or not. But currently there is no clear information about their cold wallet address.