The moment you deposited your money with a bank, the ownership is transferred to the bank.
Your status is that of a creditor to the bank, and the bank is, in law, a debtor to you.
You are deemed to have lent your money to the bank for that bank to apply to its banking business - even to gamble in the biggest casino in the world, the global derivatives casino. You have become a creditor - an unsecured creditor.