This week, six Biotechnology stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

ARIAD Pharmaceuticals, Inc. (NASDAQ:ARIA) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. ARIAD Pharmaceuticals is an oncology company that focuses on the discovery, development, and commercialization of medicines for cancer patients. For more information, get Portfolio Grader’s complete analysis of ARIA stock.

Neurocrine Biosciences, Inc.’s (NASDAQ:NBIX) ratings are looking better this week, moving up to a B from last week’s C. Neurocrine Biosciences is focused on the discovery and development of therapeutics for neuropsychiatric, neuroinflammatory, and neurodegenerative diseases and disorders. For more information, get Portfolio Grader’s complete analysis of NBIX stock.

This week, Array BioPharma (NASDAQ:ARRY) pushes up from a C to a B rating. Array BioPharma is a biopharmaceutical company focused on the discovery, development and commercialization of targeted small molecule drugs to treat patients afflicted with cancer, inflammatory and metabolic diseases. For more information, get Portfolio Grader’s complete analysis of ARRY stock.

Celldex Therapeutics, Inc. (NASDAQ:CLDX) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. Celldex Therapeutics is engaged in the discovery, development and commercialization of products that harness the human immune system to prevent and treat disease. Shares of CLDX have increased 5.3% over the past month, better than the 1.3% decrease the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of CLDX stock.

This is a strong week for Insmed Incorporated (NASDAQ:INSM). The company’s rating climbs to B from the previous week’s C. Insmed develops and commercializes drugs that treat metabolic diseases, endocrine disorders and oncology. For more information, get Portfolio Grader’s complete analysis of INSM stock.

This week, Neuralstem, Inc.’s (AMEX:CUR) ratings are up from a C last week to a B. Neuralstem is a biotherapeutics company utilizing its Human Neural Stem Cell technology to develop cures for diseases of the CNS. For more information, get Portfolio Grader’s complete analysis of CUR stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.