On the Portfolio Grader database this week, the energy services, electrical equipment, marine, construction and engineering and metals and mining sectors are among the worst.

The energy services sector is dragging, with 91% of its stocks (53 out of 58) rated a “sell”. CARBO Ceramics (CRR), Tidewater (TDW) and Transocean (RIG) are pushing the sector down with F grades.

The electrical equipment sector is lagging this week with 65% of its stocks (17 out of 26) rated a “sell”. Out of the electrical equipment stocks, General Cable Corporation (BGC), Graftech International Ltd (GTI) and Encore Wire Corporation (WIRE) are near the bottom with F’s.

The marine sector is trailing behind others this week, with 57% of its stocks (4 out of 7) rated a “sell”. Seaspan Corporation (SSW) and Kirby Corporation (KEX) are dragging down the sector overall, each earning a low grade of F. Diana Shipping (DSX) currently ranks D.

With 52% of its stocks (11 out of 21) rated “sell,” the construction and engineering sector is struggling this week. Empresas ICA SAB de CV Sponsored ADR (ICA), KBR, Inc. (KBR) and Jacobs Engineering Group (JEC) are all currently earning F’s.

The metals and mining sector looks weak, with 52% of its stocks (45 out of 86) rated a “sell”. Out of the metals and mining stocks, Vale S.A. Sponsored ADR (VALE), Freeport-McMoRan, Inc. (FCX) and Companhia Siderurgica Nacional Sponsored ADR (SID) are near the bottom with F’s.

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.