Looking to trim your exchange-traded fund positions? Here are 25 sell-worthy options. TheStreet.com Ratings has graded these funds E-minus, the lowest mark we give. Nine of them invest in energy and natural resources, the largest industry grouping. The worst-rated fund, the Claymore/SWM Canadian Energy Income Index ETF ( ENY), has fallen 69% in the past year, the fourth-biggest loss of the group. The fund suffered after the price of West Texas intermediate crude oil crashed to less than $45 a barrel after topping $140 in June. Its top two holdings, Enerplus Resources Fund ( ERF) and Penn West Energy Trust ( PWE) have each declined 21% this year. Together, they account for 16% of the fund's assets. TheStreet.com Ratings relies on a quantitative model to evaluate a fund's risk-adjusted performance and assign a grade. Grades of D or less amount to "sell" recommendations. There are also "reward" and "risk" grades, which reflect a fund's performance and volatility. The ETFs below earned the lowest "overall" ratings, the worst combination of the two components. To view the top-rated funds, click here.