Large companies in the health care space, such as drugmaker Merck (NYSE:MRK), are typically insulated from general secular trends and tend to make good defensive plays for long-term investors. However, this rule of thumb should be taken with a grain of salt; not every pharmaceutical company is the right fit for your portfolio, and investors always need to consider the bull and bear theses of their investments. In this video, our health care analyst dives into the bear thesis for Merck.  

Max Macaluso, Ph.D. 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.