This episode of The Motley Fool's Market Checkup drills down on the hottest headlines and biggest market movers in the health-care sector. 

In this video, health-care analysts David Williamson and Max Macaluso discuss Achillion Pharmaceuticals' no good, very bad day. The company announced after the market closed on Friday that its hepatitis C drug sovaprevir would remain on clinical hold. Shares have been slashed in half by investors.

Achillion is in a tough position. It has a broad range of hep C drugs, but it is far back in development from its deep-pocketed competitors. Gilead and Johnson & Johnson have drugs under FDA review right now, while Gilead and AbbVie each plans to offer interferon free "drug cocktails" soon after. Combine that with a litany of safety-related clinical holds in next-gen hep-C treatments and investors hoping for a quick resolution for what looked to be a drug-to-drug related interaction are left disappointed.

David and Max take a closer look at how this delay impacts Achillion, why investors were even more skittish after the conference call, and if the stock's sell-off made it a bad news buy.