Shares of Gilead Sciences (NASDAQ:GILD) were up nearly 4% today ahead of its earnings call after market close. Sales of its drug Sovaldi are absolutely crushing expectations, and Baird has recently upgraded the stock to "outperform" and given it a price target of $103.

In this video, Motley Fool health-care analyst David Williamson looks at Sovaldi sales and how much Gilead stands to benefit, and also how this may be a rising tide lifting other boats, including AbbVie (NYSE:ABBV).

David Williamson owns shares of AbbVie. The Motley Fool recommends Gilead Sciences. 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.