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 Silver Spring Networks, (NYSE:SSNI) plunged more than 23% Friday after the smart-grid systems maker reported disappointing preliminary fourth-quarter results.

So what: Quarterly adjusted sales are now expected to rise around 5% year over year to $88 million to $89 million. That should translate to adjusted earnings in the range of minus $0.01 per share to breakeven results. Meanwhile, analysts were modeling earnings of $0.18 per share on the same basis, with sales of $104.92 million.

Now what: And while CEO Scott Lang did note that the company managed to grow its total backlog to a record $875 million in 2013, good for 17% year-over-year growth, he also went on to explain, "We did not close a few expected deals which affected our fourth quarter results."

That seems fair enough, as the company's highly competitive projects don't always go as planned. But it also stands as little consolation for shareholders still reeling from Silver Spring's loss last August in a competitive bid for a 12-year, $18.5 billion contract from the U.K.'s Department of Energy. Still, the backlog proves the company has plenty of opportunities to grow.

With shares currently trading 47% below 52-week-highs, and less than a dollar above last year's IPO price at $17 per share, today's pullback could potentially prove a solid buying opportunity for patient long-term investors. At the very least, while noting significant risk still exists, I think investors would be wise to add Silver Springs to their watchlists.