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 Horizon Pharma (NASDAQ:HZNP), a specialty pharmaceuticals company that develops therapies to treat arthritis, pain, and inflammatory diseases, soared as much as 23% after announcing its preliminary fourth-quarter results.

So what: According to Horizon Pharma's preliminary results, the company expects to report total net revenue of $31.9 million to $32.4 million in the fourth quarter as prescriptions for Duexis and Rayos increased by 13% and 18%, respectively, from the sequential third quarter. By comparison, Wall Street estimates had only called for Horizon Pharma to deliver $27.4 million in net revenue for the fourth quarter. Horizon Pharma also provided an update on Vimovo, which it acquired the U.S. rights to from AstraZeneca (NYSE:AZN) in November for $35 million. The key point of this update is that Vimovo prescriptions increased 4% in December compared to November, giving investors early signs that this purchase may have been a smart move.

Now what: As you can tell by these results, Horizon Pharma is on the cusp of a major growth period. Normally, growth periods will hit snags every now and then, but with revenue growth of roughly 300% in fiscal 2013, and projections of better than 150% sales growth in 2014, more risk-willing biotech-savvy investors have to be taking notice of Horizon. Furthermore, the Vimovo purchase should be the catalyst that pushes Horizon into profitable territory this year. While the company is pricey on a forward-earnings basis, I've seen no signs that would point to a slowdown in top-line growth or EPS momentum anytime soon. As such, I could see a scenario where Horizon Pharma heads even higher from here.

Horizon Pharma may be soaring today, but even it may struggle to keep pace with this top stock in 2014
There's a huge difference between a good stock and a stock that can make you rich. The Motley Fool's chief investment officer has selected his No. 1 stock for 2014, and it's one of those stocks that could make you rich. You can find out which stock it is in the special free report "The Motley Fool's Top Stock for 2014." Just click here to access the report and find out the name of this under-the-radar company.

Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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.