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 optical networking specialist Infinera (Nasdaq: INFN) spiked 17% on Friday after its quarterly results easily topped Wall Street expectations.

So what: Infinera's fourth-quarter beat was so wide -- adjusted EPS loss of just $0.06 versus the consensus loss of $0.13 -- that analysts have no choice but to raise their valuation estimates. The company has been hit by weak demand and higher costs over the past year, but today's results suggest that things are starting to turn around.

Now what: Don't let today's pop keep you from looking into the stock. "We benefited from unanticipated year-end budget spending by a number of customers and were able to execute to our disaster recovery process following the historic flooding in Thailand," said CEO Tom Fallon. When you couple that strong sales momentum with its debtless balance sheet, Infinera still seems like a pretty solid opportunity.

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