Five energy services stocks are moving up in their overall rating this week, according to the Portfolio Grader database. Every one of these is graded an “A” (“strong buy”) or “B” overall (“buy”).

Synthesis Energy Systems, Inc. (SYMX) is bumping up its rating from a C (“hold”) to a B (“buy”) this week. Synthesis Energy Systems designs, invests in, builds, owns, and operates utility plants for industrial customers. In Portfolio Grader’s specific subcategory of Sales Growth, SYMX also gets an A. For more information, get Portfolio Grader’s complete analysis of SYMX stock.

Exterran Partners, L.P. (EXLP) boosts its rating from a C to a B this week. Exterran Partners offers natural gas compression services. Shares of the stock have been trading at an exceptionally rapid pace, up threefold from the week prior. The stock’s dividend yield is 2.1%. For more information, get Portfolio Grader’s complete analysis of EXLP stock.

Parker Drilling Company (PKD) earns a B this week, jumping up from last week’s grade of C. Parker Drilling provides contract drilling and related services. Shares of PKD have increased 6.3% over the past month, better than the 1.7% decrease the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of PKD stock.

CARBO Ceramics (CRR) gets a higher grade this week, advancing from a C last week to a B. CARBO Ceramics manufactures and supplies resin-coated ceramic and resin-coated sand proppants primarily used in the hydraulic fracturing of natural gas and oil wells in the United States and internationally. Investors have pushed the stock price up 17.3% over the past month. For more information, get Portfolio Grader’s complete analysis of CRR stock.

This week, Helmerich & Payne, Inc. (HP) pushes up from a C to a B rating. Helmerich & Payne provides contract drilling of oil and gas wells in the Gulf of Mexico and South America. Investors seem to agree with the upgraded status of the stock and have pushed the stock up 16% over the past month. At present, the stock has a dividend yield of 2.5%. For more information, get Portfolio Grader’s complete analysis of HP 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.