The phrase "worst performers" refers to individuals, groups, or things that do not do well or achieve desired results compared to others. Full definition
The school is among the state's worst performers in terms of student test scores. (aaeteachers.org)
No one knows which sectors will be the best and worst performers over the next five years, which is why maintaining a reasonable level of diversification is important. (simplysafedividends.com)
Bad performers do not see the need to improve since they are sure they will play anyway. (justarsenal.com)