This week, three Building Products stocks are improving their overall rating on Portfolio Grader. Each of these rates 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. For more information, get Portfolio Grader’s complete analysis of AAON stock.

This week, NCI Building Systems, Inc.’s (NYSE:NCS) ratings are up from a C last week 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 14.4% 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 showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). 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.