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 consulting and engineering services specialist Tetra Tech (NASDAQ:TTEK) sank 13% today after the company's revised third-quarter outlook disappointed Wall Street.

So what: For the third quarter, management expects to record about $50 million in restructuring costs related to its Eastern Canada and mining operations, as well as $45 million in charges related to disputed project claims, triggering plenty of concern over its profitability going forward. While $40 million of the restructuring costs will be one-time charges, analysts are worried that the stock's premium earnings multiple will be challenged even further.

Now what: Management now sees a third-quarter loss of $0.30 to $0.50 per share on revenue of $440 million to $490 million, versus a prior view of a $0.32 to $0.42 profit on revenue of $525 million to $575 million.

"The actions we are taking in the third quarter proactively address changes in the market and right-size our operations to immediately return the company to its historical profitability and trend of margin improvement," Chairman and CEO Dan Batrack reassured investors. With the stock now off more than 25% from its 52-week highs and trading at a price-to-sales of 0.8, now might even be an opportune time to buy into that improvement.

Interested in more info on Tetra Tech? Add it to your watchlist.