NEW: Vanguard Turns 50 But Founder Jack Bogle's Dream Still Not Yet Realized.. Bogle said in 1991 "the first sign that Vanguard’s mission has created a better world for the investor will be when our market share begins to erode." But its share is still expanding, now 28% of all US fund assets and fast on way to 30%, which is double the #2 firm and double the industry's old high water mark set by Fidelity in the '90s. (Everything about this tweet is just insane.. someone really should write a book about it)