Even smallish institutional investors can and do short stocks all across the spectrum on a daily basis to suit their particular needs. And there isn't an exchange on earth subject to the same strict protocols and regs as any here in the states, that's ridiculous. Yes MM's short in the very short term to make a market, that's why they are called market makers. And some of them also short stocks in varied time spans according to their needs, and they are mostly algorithm and computer generated. MM's don't sit the lunchroom rubbing their hands together deciding who to go after next, they parse the data, plug it into various algorithms and go from there, putting either buying or selling pressure on the stocks according to their customers needs. The "short interest/short volume" argument is simplistic and far from complete.
Market Data 
Markets 
AI
