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 Spectranetics (NASDAQ:SPNC), a cardiovascular medical device maker, surged by as much as 10.7% today after the FDA approved its Turbo Tandem and Turbo Elite atherectomy devices for treating in-stent restenosis, or ISR, a condition of narrowing blood vessels following the use of stents.

So What: The regulatory win came after Spectranetics's laser atherectomy devices posted a big win in a clinical study, boasting a 94% success rate in treating patients with ISR alongside balloon angioplasty, the traditional treatment for the condition. By contrast, the control group of patients treated with angioplasty alone managed just an 83% success rate in the trial.

Now What: Spectranetics's stock has gotten back to its winning ways after a subpar 2014, continuing its 130% run-up over the past two years behind an approval that should open up a big market for the company's devices. The U.S. sees more than 115,000 ISR treatments conducted every year, according to the company's figures, and traditional balloon angioplasty procedures alone run a significant risk of recurring vessel narrowing for patients.

Spectranetics is hoping to cut back on that recurrence rate, improving outcomes for patients while also introducing a game-changer into how medical professionals treat this condition. The company estimates a potential market of $350 million annually in the U.S. alone, with a $750 million market worldwide. That's a significant opportunity for a device maker that posted sales of just over $150 million in 2013, and today's approval keeps this company's long-term outlook bright.