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

This week, Waste Management (NYSE:WM) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Waste Management provides collection, transfer, recycling, disposal and waste-to-energy services. The stock price has dropped 8.4% over the past month, worse than the 2.8% increase the S&P 500 has seen over the same period of time. For a full analysis of WM stock, visit Portfolio Grader.

EnergySolutions (NYSE:ES) earns a D this week, falling from last week’s grade of C. EnergySolutions provides technical services to the nuclear industry. The stock gets F’s in Cash Flow and Margin Growth. For more information, get Portfolio Grader’s complete analysis of ES stock.

Waste Connections‘s (NYSE:WCN) rating falls this week to a F (“strong sell”), down from last week’s D (“sell”). Waste Connections is an integrated solid waste services company that provides solid waste collection, transfer, disposal and recycling services in mostly secondary markets in the western and southern United States. To get an in-depth look at WCN, get Portfolio Grader’s complete analysis of WCN stock.

This week, Iron Mountain (NYSE:IRM) drops from a C to a D rating. Iron Mountain provides records and information management services to customers in North America, Europe, Latin America and Asia Pacific. The stock currently has a trailing PE Ratio of 35.90. For a full analysis of IRM stock, visit Portfolio Grader.

This is a rough week for Viad Corp. (NYSE:VVI). The company’s rating falls to D from the previous week’s C. Viad provides high-quality, place-based marketing services in North America, the United Kingdom and the United Arab Emirates, as well as travel and recreation services in the United States and Canada. The stock also gets an F in Margin Growth. The stock’s trailing PE Ratio is 209.80. For more information, get Portfolio Grader’s complete analysis of VVI stock.

Slipping from a C to a D rating, Quad/Graphics (NYSE:QUAD) takes a hit this week. Quad/Graphics is a commercial printing company with image centers and photography studios nationwide and plants across the country. The stock gets F’s in Earnings Momentum and Earnings Surprise. Share prices fell 6.7% over the past month. As of Oct. 3, 2012, 14.3% of outstanding Quad/Graphics shares were held short. To get an in-depth look at QUAD, get Portfolio Grader’s complete analysis of QUAD 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.