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

This week, Workday, Inc. Class A (WDAY) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Workday provides software-as-a-service solutions for managing global businesses, combining a lower cost of ownership with an innovative approach to business applications. For Portfolio Grader’s specific subcategory of Equity, WDAY also gets an F. To get an in-depth look at WDAY, get Portfolio Grader’s complete analysis of WDAY stock.

SRS Labs’ (SRSL) rating weakens this week, dropping to a D versus last week’s C. SRS Labs develops and licenses audio and voice enhancement technologies. The stock gets F’s in Earnings Growth and Margin Growth. For more information, get Portfolio Grader’s complete analysis of SRSL stock.

Taomee Holdings Ltd. Sponsored ADR’s (TAOM) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). Taomee Holdings produces children’s entertainment. The stock receives F’s in Earnings Growth, Earnings Momentum and Earnings Revisions. Margin Growth and Sales Growth also get F’s. To get an in-depth look at TAOM, get Portfolio Grader’s complete analysis of TAOM stock.

Slipping from a C to a D rating, Mavenir Systems, Inc. (MVNR) takes a hit this week. The stock gets F’s in Earnings Revisions and Equity. For more information, get Portfolio Grader’s complete analysis of MVNR stock.

Varonis Systems, Inc. (VRNS) is having a tough week. The company’s rating falls from a C to a D. The stock gets F’s in Earnings Revisions and Equity. To get an in-depth look at VRNS, get Portfolio Grader’s complete analysis of VRNS stock.

This week, Zix Corporation’s (ZIXI) rating worsens to a D from the company’s C rating a week ago. Zix provides secure, Internet-based applications in a Software-as-a-Service (SaaS) model. The stock gets F’s in Earnings Growth, Earnings Momentum and Earnings Surprise. The stock’s trailing PE Ratio is 73.90. For more information, get Portfolio Grader’s complete analysis of ZIXI stock.

Digimarc Corporation (DMRC) experiences a ratings drop this week, going from last week’s C to a D. Digimarc provides media identification and management solutions to commercial entities and government customers in the United States and internationally. The stock gets F’s in Earnings Momentum, Earnings Revisions and Equity. Margin Growth and Sales Growth also get F’s. To get an in-depth look at DMRC, get Portfolio Grader’s complete analysis of DMRC 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.