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.