Three Building Products 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”).

This week, AAON, Inc. (NASDAQ:AAON) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). AAON manufactures and sells air-conditioning and heating equipment. In Portfolio Grader’s specific subcategory of Earnings Momentum, AAON also gets an A. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of AAON stock.

NCI Building Systems, Inc. (NYSE:NCS) shows solid improvement this week. The company’s rating rises from a C to a B. NCI Building Systems designs, manufactures, and markets metal engineered building systems and products for the building industry. The stock price has risen 6.4% 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 NCS stock.

This week, PGT, Inc. (NASDAQ:PGTI) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. PGT manufactures and supplies residential impact-resistant windows and doors. For more information, get Portfolio Grader’s complete analysis of PGTI 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.