It would be easy to dismiss Synaptics (NASDAQ:SYNA) as a downtrodden, mid-cap stock not worth a look from growth-oriented investors, particularly after the last couple of months. After announcing fiscal 2015 annual and Q4 earnings on July 30, Synaptics stock inched up to nearly $80 a share in the few days that followed. But the semi-good tidings weren't meant to last, at least for existing Synaptics shareholders.

For those not overly familiar with Synaptics, its 25% drop in share price the past couple of months would seem to indicate its last quarter and fiscal year must have been a dud, right? As it happens, nothing could be further from the truth, which is a primary reason why Synaptics warrants a place on a growth investor's "stocks to watch" list. Better still, Synaptics offers a host of other reasons it's worth a good, hard look.

By the numbers
It's not often a company reports the kind of quarter and fiscal year Synaptics did in July and gets punished for it, but that's exactly what happened. Last quarter's record-setting $479 million in sales was a 52% improvement compared to the year-ago period and that paled in comparison to its annual results. For the year, Synaptics enjoyed a whopping 80% increase in revenue, to $1.7 billion, and by all accounts, investors can expect more of the same.

Despite spending heavily last quarter, particularly for research and development, Synaptics grew Q4 non-GAAP (excluding one-time items) earnings per share to $1.57, a respectable 8% improvement compared to 2014. Unfortunately, or fortunately for investors in search of value, the $1.57 EPS Synaptics generated in Q4 was below analyst estimates of $1.66.

But it was on annual basis that Synaptics' non-GAAP EPS really impressed -- by climbing 40% year over year. And that kind of explosive growth is expected to continue. Synaptics CFO Wajid Ali forecast sales will come in between $450 million to $490 million for the current quarter, an astounding increase of 59% to 73% versus last year.

Right place, right time
Such strong results and expectations for ongoing improvement raises the question: How is Synaptics able to post these kind of results? The answer is that its product mix couldn't be more in demand. Synaptics' suite of touchscreen, display, and biometric fingerprint ID solutions are ideally suited to a world that is moving away from traditional PCs and opting instead for touchscreen laptops and mobile devices.

Last quarter was the perfect demonstration of the strength of Synaptics' product suite. Of its $479 million in revenue in Q4 , 89% -- equal to $426.6 million -- was derived from its mobile division. The 76% spike in mobile-related revenue more than made up for the decline in PC sales, as evidenced by the record quarter and year Synaptics posted.

Let's talk value
Naysayers may point to the trailing price-to-earnings-ratio of 22 as confirmation Synaptics is trading at a reasonable valuation right now, recognizing its precipitous stock price decline of late. But long-term growth investors should be more interested in what's coming, not what's already happened.

From that perspective, Synaptics' relative value is undeniable. Looking ahead, Synaptics' forward P/E of 8 is almost embarrassingly low considering its phenomenal growth, and investors can expect more of the same going forward.

Though hardly the sole reason to invest in any stock, it is telling that of the 14 analysts who follow Synaptics regularly, 11 of them have a "buy" recommendation. Even more intriguing is that the consensus price target for Synaptics is an eye-popping $94.82 a share. To put that into perspective, as of this writing Synaptics is trading around $65 a share.

In addition to all of the positives noted above, Synaptics continues to announce sales wins with several up-and-coming Chinese mobile device manufacturers, a market many industry pundits point to as one of the fastest growing on the planet.

When it's said and done, Synaptics boasts outstanding top- and bottom-line growth, a forward P/E that screams "undervalued," and a product lineup that is spot-on in today's mobile world. Based on all that, there's no earthly reason Synaptics is trading at these depressed levels, but it is. Which is exactly why Synaptics belongs on a very, very short list of stocks to consider for mid-cap growth investors.

Tim Brugger has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.