C-Suite Squawk: Ariad Pharmaceuticals, Inc., Uniqure NV, and Sothebys

It's a big day on the corporate front, with management shake-ups at seemingly every turn. Three companies, in particular, announced major changes to their executive ranks -- specifically, drugmakers Ariad Pharmaceuticals, Inc. (NASDAQ:ARIA) and Uniqure NV (NASDAQ:QURE), as well as auction house Sothebys (NYSE:BID).

ARIA announced Paris Panayiotopoulos will be its next president and CEO, succeeding Harvey Berger, after succumbing to pressure from Sarissa Capital Management. The news has the stock 3.5% lower at $6.01, and off nearly 68% since its late-August two-year high of $10.07. Earlier, the shares were down more than 10%, landing them on the short-sale restricted list.

This is great news for short sellers and option bears alike. For starters, 17.3% of Ariad Pharmaceuticals, Inc.'s float is sold short -- equivalent to 13 days' worth of trading activity, at typical volumes. For another, the stock's 50-day put/call volume ratio of 1.09 at the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX) ranks a mere 3 percentage points from a 52-week high.

Moving along, following news that Dan Soland has been appointed the company's new CEO, QURE has dropped 6.5% to trade at $16.27. In fact, the shares have gone ice cold this month, tanking 13.5%.

That hasn't dampened the optimism on Wall Street. During the last 10 days at the ISE, CBOE, and PHLX, for instance, traders have bought to open 12.4 Uniqure NV calls for every put. Separately, all 11 analysts tracking the stock have doled out a "strong buy" endorsement. If the shares don't heat up soon, a capitulation among these bulls could exacerbate their recent technical troubles.

Finally, BID has slipped 0.5% at $26.35, after the company's CFO Patrick McClymont announced his resignation, effective Jan. 1 -- following months of activist pressure. Throwing salt on the wound, Stifel cut its price target on the stock to $30 from $38.

Longer term, Sothebys has been a disaster, sliding close to 39% year-to-date. Accordingly, short sellers have been active. Over 17% of the stock's float is dedicated to short interest, and would take two weeks to cover, at average trading levels.