The Friday File: Earlier this week, John Bogle, a crusader for investor’s rights and the man who virtually single-handedly invented index funds, died at 89. His relentless focus on cutting investment fees at his firm (Vanguard), and the reduction in fees at other firms that resulted due to competition has probably saved investors $1 trillion, that’s $1,000,000,000,000, since he began the first index fund in 1975. Thank you, John!