"How much typically does an owner of a share get to loan out a share in this way?"
You've got it the wrong way around.
The mums and dads through their superfunds actually own the shares but the Instos control them and charge fees to the shorters, like Norge bank and Deutsche bank, to borrow and return our shares as collateral.
I have no idea where those fees that the Instos and super funds charge to despoil and exploit our shares end up but you can bet the ASX won't stop it because they benefit through the extra trades being generated on their exchange.
SXY Price at posting:
34.5¢ Sentiment: None Disclosure: Held