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 rates an F in Sales Growth. For more information, get Portfolio Grader’s complete analysis of IHC stock.

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

Slipping from a C to a D rating, Baldwin & Lyons, Inc. Class B (BWINB) takes a hit this week. 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.