This episode of The Motley Fool's Market Checkup is dedicated to the world's largest pure-play biotech stock, Gilead Sciences (NASDAQ:GILD)Market Checkup gives a full examination of Gilead's second-quarter results, takes a closer look at the company's current product portfolio, and analyzes the future drugs that have investors excited about the stock's future.

In this video, health-care analysts David Williamson and Max Macaluso drill down on Gilead's core franchise of HIV drugs. Watch and find out why Gilead put its top seller at risk of losing sales, why that would actually be a good thing for the biotech, and whether a new competitor from a Big Pharma partnership could disrupt the market.

David Williamson owns shares of Pfizer and Johnson & JohnsonFollow David on Twitter: @MotleyDavid. Max Macaluso, Ph.D., owns shares of Gilead Sciences. The Motley Fool recommends Gilead Sciences and Johnson & Johnson and owns shares of Johnson & Johnson. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.