The study looked at the collective performance of each fund complexs offerings over one, three, five and 10 years ending March 31.
Seventy-nine percent of T. Rowe Prices funds outperformed their peers over the past one and three years, 77% bested their peers over the past five years, and 74% over the past decade.
Vanguard also put in a strong showing, with 68% of this companys funds outperforming their peers over the past year, 76% over the past three years, 79% over the past five years and 82% over the past 10 years.
However,