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.

Alison Southwick has no position in any stocks mentioned. David Williamson 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.