I guess you mean stake, right? If you are talking about staking, then ETH can't be staked yet. It uses proof of work, where you have to mine the coins. There are exchanges that allows you to "stake" your coins, but that is not staking. You are just lending your coins to those exchange and they share some profit with you. Remember, when you store your coins in an exchange and give it to them, they are no longer yours. Like others said, not your keys, not your coins. You just trust with your coins. If they get hacked, your coins are gone. I am not sure but I have heard that you can stake your coins for ETH 2.0, but once you stake it, you will have your coins locked until ETH 2.0 has been completely rolled out.