Uh, no, your broker never gets the stock for your account - unless you ask for delivery of the certificates. Your broker floats the shares in various ways for the duration. SEC recently announced it will be investigating various practices involving "short selling".
Money from nothing...
RE: “Your broker floats the shares in various ways for the duration.”
This happens on the floor. Runners (is that the name of the persons on the floor?) Have to make up where they lost through other trades. Sometimes you can get your ass handed to at the bell. Other times (I assume) it’s a win for the brokerage house, meaning a Christmas bonus.