This week, the ratings of 10 Biotechnology stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

AMAG Pharmaceuticals, Inc.’s (AMAG) rating weakens this week, dropping to a F versus last week’s D. AMAG Pharmaceuticals, Inc. utilizes its proprietary technology for the development and commercialization of a therapeutic iron compound to treat anemia and novel imaging agents to aid in the diagnosis of cancer and cardiovascular disease. The company also gets F’s in operating margin growth, earnings growth, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of AMAG stock.

This week, Adamas Pharmaceuticals, Inc. (ADMS) drops from a C to a D rating. The company also gets F’s in sales growth, operating margin growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ADMS stock.

Ardelyx, Inc. (ARDX) slips from a D to a F this week. The company also gets F’s in sales growth, earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ARDX stock.

Karyopharm Therapeutics, Inc. (KPTI) experiences a ratings drop this week, going from last week’s D to a F. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of KPTI stock.

This is a rough week for ADMA Biologics, Inc. (ADMA). The company’s rating falls to D from the previous week’s C. The company also gets F’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of ADMA stock.

Merrimack Pharmaceuticals, Inc. (MACK) gets weaker ratings this week as last week’s D drops to a F. Merrimack Pharmaceuticals, Inc. is focused on the discovery, development and commercialization of drugs for the treatment of immunological and autoimmune diseases with an initial focus on cancer. The company also gets F’s in earnings revisions and free cash flow. For more information, get Portfolio Grader’s complete analysis of MACK stock.

PDL BioPharma, Inc. (PDLI) earns a F this week, moving down from last week’s grade of D. PDL BioPharma, Inc. engages in intellectual property asset management and patent portfolio and related assets investment activities. The company also gets F’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of PDLI stock.

This week, VistaGen Therapeutics, Inc.’s (VTGN) rating worsens to a F from the company’s D rating a week ago. The company also gets F’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of VTGN stock.

Slipping from a C to a D rating, Aptose Biosciences Inc. (APTO) takes a hit this week. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of APTO stock.

Aviragen Therapeutics Inc (AVIR) is having a tough week. The company’s rating falls from a D to a F. The company also gets F’s in earnings growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of AVIR 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.