There are many reasons for the recent weakness in biotech stocks. As the year ends, some investors have definitely decided to lighten up on their winners. Catalyst Pharmaceuticals (CPRX) was the best-performing stock between January and the end of September. And here's what Catalyst looked like in October: ^NBI data by YCharts
I probably had something to do with the Catalyst sell off. Acadia Pharmaceuticals (ACAD - Get Report) was the second-best performing stock January through September. And in October: ACAD data by YCharts
Celldex Therapeutics (CLDX - Get Report): Third-best return January through September. Not in October: nd CLDX data by YCharts
Picking up the pattern? Here's Biocryst Pharmaceutics (BCRX - Get Report), fourth best until Octoer: ^NBI data by YCharts
-- Reported by Adam Feuerstein in Boston. Follow Adam Feuerstein on Twitter.