At the end of 2001, the five largest pharmaceutical companies in the United States had a combined market capitalization in excess of $700 billion, nearly twice the total $384 billion market capitalization of public biotechnology companies in the United States, according to Burrill & Company. That gap has since evaporated. By the end of 2007, the top five U.S. pharmaceutical companies had a combined market capitalization of about $425 billion, less than the $455 billion value of their biotech brethren. The shrinking value of pharmaceutical companies has had much to do with such well publicized problems as the expiring patents on blockbusters, key products withdrawn from the market, and weaknesses in their product pipelines. The total value of the public biotechnology sector, however, has been muted by Big Pharma’s appetite to acquire these companies. Between 2005 and 2007 alone, pharmaceutical companies purchased biotechnology companies with a combined value of $49 billion. Below, a chart maps the changing value of these two sectors.