Four Metals and Mining 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”).

Sandstorm Gold Ltd.‘s (AMEX:SAND) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). In Portfolio Grader’s specific subcategories of Earnings Growth and Sales Growth, SAND also gets A’s. For more information, get Portfolio Grader’s complete analysis of SAND stock.

Franco-Nevada (NYSE:FNV) gets a higher grade this week, advancing from a C last week to a B. Franco-Nevada is a resource royalty and investment company. Shares of FNV have increased 19% over the past month, better than the 3.6% increase the S&P 500 has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of FNV stock.

Grupo Simec (AMEX:SIM) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. The stock has a trailing PE Ratio of 9.9. For more information, get Portfolio Grader’s complete analysis of SIM stock.

This week, DRDGOLD (NYSE:DRD) pushes up from a C to a B rating. DRDGOLD engages in the exploration, extraction, processing, and smelting of gold in South Africa. For more information, get Portfolio Grader’s complete analysis of DRD 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.