Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of medical-device maker Tornier (NASDAQ: TRNX) were getting tripped up today, falling as much as 15% after a downgrade from Northland Securities.

So what: The downgrade, from "market perform" to "underperform," came on the heels of yesterday's surprise announcement that 54-year-old CEO Doug Kohrs was leaving the company.

"The sudden nature of the announcement combined with the recent deceleration in sales growth could raise questions 2013 outlook for the company," Northland said.

Tornier has missed EPS estimates in its last two quarters with a $0.29 loss in its most recent quarter.

Now what: Countering Northland's opinion was investment house Piper Jaffray, which reaffirmed its overweight rating on Tornier today. Speculating about Kohrs' departure is unlikely to lead to any sure answers, but investors may want to be reminded that Tornier has yet to turn a profit in its three-year history, and with growth slowing this could be a problem. Analysts are eyeing small losses for the next two quarters as well. I'd wait for new CEO David Mowry to prove himself by getting the company into positive territory before getting on board.

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