So I'm trying to learn about IB right now and I want to make sure I am understanding this correctly. In my book it is describing how IB's make money and it says "Investment bankers usually rely on selling financial instruments, in a process called underwriting. By selling financial instruments to investors, the bankers raise the money that's provided to the people, companies, and governments that have productive uses for it."

So to me this means that IBs make their money from selling the stocks or bonds (or whatever financial instrument) they underwrote (stock the IB bought due to not being able to sell it all?) to other new investors. Is this right? If not how do IBs make money?