How do they make money?
* mortgage - using some billionaires account to buy housing properties and leasing them
* estate and lands with same patterns
* SMS alert charges
* Transfer charges
* Syphons dormant accounts or dead people accounts that are inactive with enough money in it.
* ATM and investment cards
* sales of currencies like dollar to naira
* preparation of international documents
* savings people's valuables like gold, certificate, court documents, WILLS, and so on.
This is what makes financial institutions very wealthy.
From everything that you have listed, it is obvious that the summary is of how banks generate income is through other people's money. That is how financial institutions stay wealthy. They use other people's money, invest in businesses and make a massive ROI. Banks don't have money of their own. In addition, if you have ever taken out a loan from a bank, you'd be amazed by how high the interest rate is. It's crazy. This is another way they generate income. Other people's money and high interest rate sums it all.