One thing with biotechs is that I think you've got to diversify within them. One mistake or bad result and the company could be over. Also, there's a danger of technologies overtaking each other quickly so that a new product can be obsolete in six months, like what is happening with computer gadgets. However, some products in the medical field get orphan status, which means they get a monopoly (yes, a monopoly!) for treating particular diseases for 7 years.
