This week, 4 Software stocks are worse, according to the Portfolio Graderdatabase. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This is a rough week for ANSYS, Inc. (ANSS). The company’s rating falls to D from the previous week’s C. ANSYS, Inc. develops and markets engineering simulation software and technologies used by engineers and designers working in fields such as aerospace, electronics, biomedical, energy, and defense. For more information, get Portfolio Grader’s complete analysis of ANSS stock.

Manhattan Associates, Inc. (MANH) declines this week from a C to a D. Manhattan Associates, Inc. provides information technology solutions for distribution centers. For more information, get Portfolio Grader’s complete analysis of MANH stock.

This week, Imperva, Inc.’s (IMPV) rating worsens to a F from the company’s D rating a week ago. Imperva, Inc. engages in the development, marketing, sale, service, and support of business security solutions that provide visibility and control over high value business data across critical systems within the data center. The company also gets F’s in earnings revisions, earnings surprise, earnings momentum, and return on equity. For more information, get Portfolio Grader’s complete analysis of IMPV stock.

Model N, Inc. (MODN) slips from a C to a D this week. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of MODN 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.