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 jewelry retailer Tiffany & Co. (TIF) popped 10% today after its quarterly results and outlook impressed Wall Street.

So what: The stock has been volatile in 2014 on concerns over sluggish demand, but today's fiscal first-quarter results -- earnings per share of $0.97 topped the consensus by $0.20 on a revenue jump of 13% -- coupled with upbeat full-year guidance are quickly easing those worries. In fact, same-store sales increased 11% during the quarter while gross margin increased 200 basis points to 58.2%, suggesting that Tiffany's cost structure and competitive position are improving.  

Now what: Management now sees full-year EPS of $4.15-$4.25, up nicely from its prior view of $4.05-$4.15, on a revenue increase in the high single-digit range. "We were pleased with the strong and broad-based sales growth across most regions and product categories and our ability to leverage those improved sales into very significant growth in operating and net earnings," said Tiffany Chairman and CEO Michael Kowalski in a press release. "Strength in fine and statement jewelry sales continued, while sales of our new or expanded jewelry collections accelerated, led by our ATLAS collection." Of course, with the stock surging to a new 52-week high today and trading at a forward P/E above 20, I'd hold out for a wider margin of safety before betting on that operating momentum to continue.