The grades of 3 Metals & Mining stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

Compania de Minas Buenaventura SAA Sponsored ADR (BVN) improves from a C to a B rating this week. Compania de Minas Buenaventura SAA Sponsored ADR is a precious metals company engaged in the exploration, mining, and processing of gold, silver and, to a lesser extent, other metals. The company also gets A’s in earnings growth. For more information, get Portfolio Grader’s complete analysis of BVN stock.

Sandstorm Gold Ltd. (SAND) shows solid improvement this week. The company’s rating rises from a C to a B. Sandstorm Gold Ltd. a gold streaming company, focuses on acquiring gold and other precious metal purchase agreements from companies that have advanced stage development projects or operating mines primarily in Canada, Brazil, and Mexico. For more information, get Portfolio Grader’s complete analysis of SAND stock.

Asanko Gold, Inc. (AKG) gets a higher grade this week, advancing from a B last week to a A. Asanko Gold, Inc. is a gold development company focusing on near term gold production. The company also gets A’s in earnings revisions. For more information, get Portfolio Grader’s complete analysis of AKG 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.