system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When a bank is robbed, do the people/companies get reimbursed by an insurance company or the bank for all of their money that has been lost?

Or is it not even their money in the bank?
gpt
It's not their money in the bank. When you give your money to the bank, it's just that: you're giving it to them. What the bank does in return is give you a slip of paper otherwise known as a "balance" of how much money you have with them, that they need to be able to pay you should you request it back.

As an added bonus: think about how a bank makes money, and incentivizes you, the customer to have them hold your money instead of another rival bank. The interest rate the bank advertises is the major selling point that most people would care about. How can they provide interest if your money just sits there? It certainly doesn't multiply on its own, otherwise under the mattress would be the ideal place to store it. Where the real money comes in is from loans. The bank uses all the money that people have given it, and attempt to make good investments on people applying for loans and earn additional income through interest they charge on top of those loans. A sound loan applicant with a well thought out business stratagem will most likely generate a return on the initial investment that the bank gave out, thus turning a profit and having more money than it had with everyone's deposits. A lot of these happen every day and it's why bankers look at "risk" which is between 'none' (a sound investment with no chance of losing money like an arbitrage) and 'high' (an unwise investment unlikely to get any money back from, such as fedoras for dolphins)

The bank gives out this Return On Investment in very small amounts as a reward for using them across all the customers. And because you don't own the money you gave them, just a balance that's good for that much money from them they give you a little extra to incentivize your continued patronage.