The grades of three Building Products stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

This week, AAON (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. For more information, get Portfolio Grader’s complete analysis of AAON stock.

NCI Building Systems (NYSE:NCS) earns a B this week, jumping up from last week’s grade of C. NCI Building Systems designs, manufactures, and markets metal engineered building systems and products for the building industry. For more information, get Portfolio Grader’s complete analysis of NCS stock.

PGT Inc. (NASDAQ:PGTI) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. PGT manufactures and supplies residential impact-resistant windows and doors. The stock price has risen 20.2% over the past month, better than the 1.3% decrease the Nasdaq has seen over the same period of time. 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.