The ratings of four insurance stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Ambac Financial Group, Inc.’s (AMBC) rating falls to a D (“sell”) this week, down from C (“hold”) the week prior. The stock also earns F’s in Portfolio Grader’s specific subcategories of Earnings Growth, Earnings Momentum, Margin Growth and Sales Growth. To get an in-depth look at AMBC, get Portfolio Grader’s complete analysis of AMBC stock.

Independence Holding Company (IHC) earns a D this week, falling from last week’s grade of C. Independence Holding sells life and health insurance. The stock also gets an F in Sales Growth. For more information, get Portfolio Grader’s complete analysis of IHC stock.

United Fire Group, Inc. (UFCS) experiences a ratings drop this week, going from last week’s C to a D. United Fire engages in writing property, casualty, and life insurance products and selling fixed annuities in the United States. The stock also rates an F in Earnings Growth. To get an in-depth look at UFCS, get Portfolio Grader’s complete analysis of UFCS stock.

Baldwin & Lyons, Inc. Class B (BWINB) earns a D this week, moving down from last week’s grade of C. Baldwin & Lyons markets and underwrites property and casualty insurance. The stock also gets an F in Earnings Surprise. For more information, get Portfolio Grader’s complete analysis of BWINB 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.