The ratings of 4 Commercial Services & Supplies stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Ritchie Bros. Auctioneers Incorporated (RBA) experiences a ratings drop this week, going from last week’s B to a D. Ritchie Bros. Auctioneers Incorporated operates as an industrial auctioneer that sells through unreserved public auctions. The company also gets F’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of RBA stock.

This week, Covanta Holding Corporation (CVA) drops from a D to a F rating. Covanta Holding Corporation develops, owns, and operates infrastructure for the conversion of waste to energy, as well as other waste disposal and renewable energy production businesses in the Americas, Europe, and Asia. The company also gets F’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of CVA stock.

Intersections Inc. (INTX) gets weaker ratings this week as last week’s C drops to a D. Intersections Inc. provides credit management and identity theft protection solutions to the consumer and small business markets on a subscription basis. The company also gets F’s in sales growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of INTX stock.

Fuel Tech, Inc. (FTEK) declines this week from a C to a D. Fuel Tech, Inc. develops and commercializes air pollution control technologies and provides engineering services. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of FTEK 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.