I posted this on the TELK mb last night. (My keyboard is better now.) It addresses how the proposed changes to Reg SHO could create a squeeze. ARTE doesn't seem like the kind of stock to worry about - unless they surprise with news. I don't see it.
They use TELK as an example. They give some data about how the market-makers handled the meltdown on Dec 26. They also note how the proposed changes might have limited the downside on that day. One thing I take from this is that the shareholder list is meaningless. Lehman was always a prominent shareholder, yet they likely held the largest short position.