This week, the overall grades of three Construction and Engineering stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Fluor’s (NYSE:FLR) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. Fluor Corporation provides professional services in the fields of engineering, procurement, construction and maintenance as well as project management services on a global basis. FLR also rates an F in Portfolio Grader’s specific subcategory of Earnings Growth. The stock price has fallen 5.5% over the past month, worse than the 2% increase the S&P 500 has seen over the same period of time. To get an in-depth look at FLR, get Portfolio Grader’s complete analysis of FLR stock.

Foster Wheeler (NASDAQ:FWLT) earns a D this week, moving down from last week’s grade of C. Foster Wheeler AG provides design, engineering, construction, manufacturing, project development and management, research, plant operations, and environmental services. The stock also gets an F in Sales Growth. Investors seem to agree with the downgrade and have pushed down the share price 22.9% over the past month.

For a full analysis of FWLT stock, visit Portfolio Grader.

Sterling Construction (NASDAQ:STRL) gets weaker ratings this week as last week’s C drops to a D. Sterling Instruction Company is a heavy civil construction company that specializes in the building, reconstruction and repair of transportation and water infrastructure. The stock receives F’s in Earnings Growth, Earnings Revisions, and Earnings Surprise. Equity, Cash Flow, and Margin Growth also get F’s. For more information, get Portfolio Grader’s complete analysis of STRL 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.