This week, the overall grades of seven software stocks are lower, according to the Portfolio Grader database. 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. In 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.

The rating of SRS Labs (SRSL) slips from a C to a D. 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.

Covisint Corp.’s (COVS) rating weakens this week, dropping to a D versus last week’s C. The stock gets F’s in Earnings Revisions, Earnings Surprise, Equity and Cash Flow. To get an in-depth look at COVS, get Portfolio Grader’s complete analysis of COVS 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 gets F’s in Earnings Growth, Earnings Momentum and Earnings Revisions. Margin Growth and Sales Growth also get F’s. For more information, get Portfolio Grader’s complete analysis of TAOM stock.

Mavenir Systems, Inc. (MVNR) 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 MVNR, get Portfolio Grader’s complete analysis of MVNR stock.

This week, Zix Corporation (ZIXI) drops from a C to a D rating. 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 trailing PE Ratio for the stock is 61.60. For more information, get Portfolio Grader’s complete analysis of ZIXI stock.

This week, Digimarc Corporation’s (DMRC) rating worsens to a D from the company’s C rating a week ago. Digimarc provides media identification and management solutions to commercial entities and government customers in the United States and internationally. The stock receives 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.