Leaving Bitcoin on an exchange means the exchange controls the "private keys." To truly own it, move it to a hardware wallet.

: Lock an account so funds can only be sent to pre-approved addresses. 2. Move to Self-Custody (Cold Storage)

For maximum security, use a regulated exchange that employs deep cold storage, undergoes regular audits, and offers advanced account-level protections. :

: A publicly traded U.S. company with SEC oversight and FDIC insurance on USD balances.