I also thought so (shorting). But now I think it is mostly...

I also thought so (shorting). But now I think it is mostly market makers (liquidity providers). Can be both I guess. In this example I think CBA is the market maker and it frequently borrows shares from others to provide liquidity. But it also holds shares which complicates the picture. During the lows of 1.50 they also had similar disclosure but then they had "buy" lines among the "borrow" and "return".

See link below.
http://www.asla.com.au/about-securities-lending/