Nothing, they simply keep it on their balance sheet. Banks can't lend reserves, they can't lend deposits. They simply create deposits by making loans. You should stop making comments and just ask questions. I am here to teach!
Banks swap reserves through Fed funds every night. Banks are short in reserve can borrow and banks has excess reserve can lend, so technically, they do lend reserves. You have demonstrated a totally lack of understanding how banking system work yet you keep spewing your stupidity 24/7. Don't you ever get tired of being exposed as a little dumb fuck?
What you have read, told, heard.....is irrelevant to me. I'm here to educate you how banking system works in real life. I don't deal with mumbo jumbo conceptualization bullshits.
Banks need reserve/deposit before they can make loans. Period. US Treasury is the most liquid market in the US. Trades are settled through clearing house same day. Do you think primary dealer just create money out of nothing to settle for those bonds? Please stop idiot. The more you post, more stupidity you show.
How the hell can banks pay interest on your saving if they do not use it to lend or invest? Are you fucking dense?