TSC Ratings provides exclusive stock, ETF and mutual fund ratings and commentary based on award-winning, proprietary tools. Its "safety first" approach to investing aims to reduce risk while seeking solid outperformance on a total return basis.Looking to add to your closed-end fund positions? Here are 25 low-rated portfolios you should consider avoiding. These funds have lost at least a quarter of their value and earned "sell"-level grades of D-plus or lower from TheStreet.com Ratings. Three of them received our lowest grade, E-minus. Ten of these closed-end funds invest internationally, and 10 have significant debt holdings. These categories have suffered as global stocks wait for a U.S. economic recovery and inflation threatens bond yields. The Advent/Claymore Global Convertible Securities & Income Fund ( AGC) was among the worst-rated funds with a grade of E. The fund buys convertible bonds from companies based anywhere in the world. At least half of its assets are in foreign securities. The fund has lost 55% of its assets in the past year. Debt that can be converted into equity generally provides a smaller yield than traditional bonds of similar quality. Shares of many companies are trading for less than their potential conversion prices. If inflation rises before equities rebound, higher interest rates on new debt might hurt Advent/Claymore's portfolio. Top holdings include Teva Pharmaceuticals ( TEVA) of Israel and Transocean ( RIG) of Switzerland. Domestic holdings include Bank of America ( BAC) and Amgen ( AMGN). The fund has 22% of its assets in financial companies, followed by 21% in health care, 10% in energy and 10% in technology.