Vanguard’s 50-year grip on U.S. funds is showing signs of slipping

Vanguard’s grip on U.S. fund assets is loosening after a half-century of uninterrupted gains.The firm’s share of assets climbed for fifty years before leveling off at 27%—double the high-water mark Fidelity set in the 1990s—and has now begun to show signs of receding.The change points to a more com…