Biopharma firm Celgene ( CELG) is another stock that's posted some blockbuster performance numbers in 2013; this $66 billion drug maker has seen its shares more than double since the start of the year. But despite that breakneck performance, CELG is well-positioned for more upside before the year is over. >>5 Stocks Under $10 Set to Soar Celgene is a biopharmaceutical firm that focuses on cancer and immunology therapies. The firm's drug portfolio includes established niche names such as Revlimid, Thalomid and Vidaza alongside newer offerings such as Pomalyst. Celgene's relatively narrow focus has been a major benefit for the firm -- it doesn't stray too far from its core competency, and as a result, the firm has been able to come up with new indications for existing therapies. Taking Revlimid to Europe should be a major revenue driver for CELG in the next couple of years despite speed bumps in getting approval; already, the drug is closing in on the $4 billion sales level this year in the U.S. With more than $2 billion in annual free cash flow generation, Celgene currently sports a balance sheet that's net cash positive to the tune of half a billion dollars -- that's in spite of a growth-by-acquisition strategy that's added considerable new drugs to the firm's pipeline in recent years. With rising analyst sentiment in Celgene this week, we're betting on shares.