There has been a lot of buzz in recent days about the idea of a bubble in the biotech space on the market today. The iShares NASDAQ Biotechnology Index (IBB -0.20%), an ETF that tracks a range of companies in the biotech space, peaked exactly a month ago, and has since lost 12% of its value, falling 3% in a single day yesterday. Investors are understandably concerned that the sell-off will lead to a continued decline in the days ahead.

In this video, Motley Fool health-care analyst David Williamson discusses why there may be some validity to the speculation of a bubble in this sector at the moment. David then gives investors his three top picks for which companies he would jump in on if a biotech pullback offered a lower price point, and why these three pharmaceutical businesses have the underlying strength to survive any market condition.