Big biotech Gilead (Nasdaq: GILD) has gone on a tremendous 200% two year run as its groundbreaking hepatitis-C cure Sovaldi is breaking all expectations with $2.3 billion in just its first quarter of availability.

This has led to nothing but praise for the big biotech and investors are riding high. But are they missing warning signs that all is not well with Gilead.

In this episode of Market Check-Up, the Motley Fool's health care focused investing show, analysts David Williamson and Michael Douglass, play a game of bull vs bear. Michael takes the banner for pro-Gilead crowd while David tries to bunch holes in his bullish argument.