Jack Bogle turned down the creator of ETFs in 1992 because he feared they'd encourage speculation. State Street launched the SPDR instead. By 1999, Vanguard was so far behind that the board enforced its mandatory retirement age — selectively — to remove Bogle. His 'firing' unlocked ETFs for Vanguard and BlackRock's eventual dominance. 99% of Vanguard's AUM came after Bogle stepped down.