Short Sellers Move Out of Amgen, Celgene, Pharmacyclics

The short interest in biotech and emerging pharmaceutical companies was mixed in the final two weeks of March. The number of shares sold short in Alexion Pharmaceuticals (NASDAQ: ALXN ), Arena Pharmaceuticals (NASDAQ: ARNA ), Illumina (NASDAQ: ILMN ), Onyx Pharmaceuticals (NASDAQ: ONXX ), Vertex Pharmaceuticals (NASDAQ: