Six Biotechnology stocks are moving up in their overall rating this week, according to the Portfolio Grader database. Every one of these is graded an “A” (“strong buy”) or “B” overall (“buy”).

Prana Biotechnology’s (NASDAQ:PRAN) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). Prana Biotechnology is an Australian biotechnology company which researches and develops therapeutic drugs used for treatment of Alzheimer’s Disease and other age-related degenerative disorders such as Parkinson’s Disease and cataracts. Shares of PRAN have increased 57.4% 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 PRAN stock.

This week, Ariad Pharmaceuticals (NASDAQ:ARIA) pushes up from a C to a B rating. 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’ (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.

Array BioPharma (NASDAQ:ARRY) is seeing ratings go up from a C last week to a B this week. 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.

This week, Celldex Therapeutics (NASDAQ:CLDX) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. Celldex Therapeutics is engaged in the discovery, development and commercialization of products that harness the human immune system to prevent and treat disease. For more information, get Portfolio Grader’s complete analysis of CLDX stock.

This week, Insmed Inc.’s (NASDAQ:INSM) ratings are up from a C last week to a B. 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.

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.