This week, the energy services, electrical equipment, marine, construction and engineering and oil and gas sectors rank lowest on the Portfolio Grader database.

The energy services sector looks weak, with 91% of its stocks (51 out of 56) rated a “sell”. With an overall grade of F, CARBO Ceramics (CRR), Transocean (RIG) and GulfMark Offshore, Inc. Class A (GLF) are weighing down the sector.

The electrical equipment sector is trailing behind others this week, with 75% of its stocks (18 out of 24) rated a “sell”. General Cable Corporation (BGC), Powell Industries, Inc. (POWL) and Graftech International Ltd (GTI) are dragging down the sector overall, each earning a low grade of F.

The marine sector is dragging, with 71% of its stocks (5 out of 7) rated a “sell”. With a grade of D, Kirby Corporation (KEX) and Diana Shipping (DSX) are weighing down the sector. Seaspan Corporation (SSW) also ranks a low F.

The construction and engineering sector is lagging this week with 67% of its stocks (14 out of 21) rated a “sell”. Among construction and engineering stocks, KBR, Inc. (KBR), Empresas ICA SAB de CV Sponsored ADR (ICA) and Jacobs Engineering Group (JEC) are lingering near the bottom with grades of F.

With 52% of its stocks (119 out of 227) rated “sell,” the oil and gas sector is struggling this week. Out of the oil and gas stocks, Stone Energy Corporation (SGY), Martin Midstream Partners (MMLP) and Peabody Energy Corporation (BTU) 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.