This week, the ratings of 4 Insurance stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

XL Group Plc (XL) is having a tough week. The company’s rating falls from a C to a D. XL Group Plc provides property, casualty and specialty products to industrial, commercial and professional firms worldwide. The company also gets F’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of XL stock.

This week, Ambac Financial Group, Inc.’s (AMBC) rating worsens to a D from the company’s C rating a week ago. The company also gets F’s in sales growth, earnings growth, earnings revisions, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of AMBC stock.

This is a rough week for MBIA Inc. (MBI). The company’s rating falls to D from the previous week’s C. MBIA Inc. provides financial guarantee insurance and other forms of credit protection. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of MBI stock.

This week, Oxbridge Re Holdings Limited (OXBR) drops from a C to a D rating. The company also gets F’s in sales growth, earnings growth, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of OXBR 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.