This week, three Gas Utilities stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

Chesapeake Utilities (NYSE:CPK) ups its rating to a B (“buy”) this week after earning a C (“hold”) in the week before. Chesapeake Utilities is a utility company engaged in the distribution, transmission, and marketing of natural gas; the distribution and wholesale marketing of propane; advanced information services; and other related businesses. In Portfolio Grader’s specific subcategory of Earnings Surprise, CPK also gets an A. For more information, get Portfolio Grader’s complete analysis of CPK stock.

This week, Atmos Energy’s (NYSE:ATO) ratings are up from a C last week to a B. Atmos Energy is engaged in the business of regulated natural gas distribution, transmission and storage. For more information, get Portfolio Grader’s complete analysis of ATO stock.

Questar (NYSE:STR) improves from a C to a B rating this week. Questar is a holding company involved in gas and oil exploration and production, midstream field services, energy marketing, interstate gas transportation and retail gas distribution. The stock price has risen 10.9% over the past month, better than the 3.4% increase the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of STR 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.