From the smallest biotech to the biggest pharmaceutical stock, The Motley Fool's Market Check-Up covers the health care sector's biggest headlines, hottest market movers, and Obamacare's ongoing rollout.

Shares of Sarepta Therapeutics (NASDAQ:SRPT) plunged more than 60% earlier this week on news that Food and Drug Administration thinks it's too early to file a new drug application for its Duchenne muscular dystrophy drug eteplirsen. The market sell-off was also spurred in part by a competing drug in this space from GlaxoSmithKline (NYSE:GSK) and Prosensa (UNKNOWN:RNA.DL) that failed its phase 3 trials. In this segment from Tuesday's episode, health care analyst David Williamson discusses whether investors who believe in this drug should consider this sell-off a buying opportunity, and why those looking to buy on the dip may need a healthy dose of patience.

Editor's Note: This video was filmed on Nov. 12, 2013.

Follow David on Twitter: @MotleyDavid.