This week, 4 Biotechnology stocks are improving their overall ratings on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

Genomic Health, Inc. (GHDX) gets a higher grade this week, advancing from a C last week to a B. Genomic Health, Inc. is a life science company, which is focused on the development and commercialization of genomic-based clinical diagnostic tests for cancer that allow physicians and patients to make individualized treatment decisions. The company also gets A’s in earnings momentum. For more information, get Portfolio Grader’s complete analysis of GHDX stock.

Vitae Pharmaceuticals, Inc. (VTAE) improves from a C to a B rating this week. The company also gets A’s in earnings revisions and earnings momentum. For more information, get Portfolio Grader’s complete analysis of VTAE stock.

Vital Therapies, Inc. (VTL) earns a B this week, jumping up from last week’s grade of C. The company also gets A’s in earnings revisions and earnings momentum. For more information, get Portfolio Grader’s complete analysis of VTL stock.

This week, NanoViricides, Inc.’s (NNVC) ratings are up from a C last week to a B. For more information, get Portfolio Grader’s complete analysis of NNVC 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.