No contradiction, when it comes to investing or trading in bitcoin, making profit is always the goal and a priority why they buys the bitcoin in the first place.
Protecting the coins is a basic concern of how to have it safe because if the security is not assured, then there is a risky possibility of loosing it and when lost all dreams and efforts are lost along.
On that note, knowing a safe wallet to store the funds such as non custodian that gives you access to your seed phrase should be remarkable including how to store your recovery keys safe from others and don't trust your private keys to third parties while storing it offline like a paper or engraved or steels is best recommended and keep it off from online storage system in other to prevent hackers from stealing the fund.
Trading or investing, if you can not secure your bitcoins, you will lose it almost immediately after you bought it. With Bitcoin blockchain, transactions are irreversible so if your devices, accounts, wallets were compromised and hackers already moved your bitcoins, transactions were confirmed even just 1 confirmation, you forever lost your bitcoin.
Custodial wallets or non-custodial wallets, if you can secure your bitcoins, it's good but the fact is with custodial wallets, you don't have private keys, so you can not control your bitcoins. If you want to have full control on your bitcoins, you must use non-custodial wallets because you own wallet mnemonic seeds, and private keys.
With any wallets, security is very important as it keeps your devices clean and avoids compromise on your wallets.
