John Bogle's biggest contribution is yet to come.

The Vanguard Group founder and father of the index fund, better known as Jack, died on Wednesday at the age of 89. A lot will be said about his influence on the financial industry in the coming days, and deservedly so. He transformed money management, making investing cheaper, simpler and more accessible than ever before, lifting the financial well-being of millions of people in the process.

Vanguard Group founder John 'Jack' Bogle is known as the father of the index fund. Credit:Bloomberg

But the most remarkable thing about Bogle is that he created billions - and perhaps trillions - of dollars in value for others and kept relatively little of it for himself. That stands in sharp contrast to the unabashed accumulation of riches among corporations, even as wealth inequality rises to alarming levels. Bogle's life is a reminder that business leaders have the power, indeed the responsibility, to shrink the wealth divide between their companies and the workers and consumers who sustain them.

If Bogle were anyone else, he'd be a billionaire. His brand of investing - buy low-cost, broad-based index funds and hold them forever - seems obvious now, but it wasn't inevitable. When Bogle launched the first index fund available to individual investors in 1976, the industry ridiculed it, calling it "Bogle's folly." Bogle was undeterred, and today Vanguard is among the largest money managers in the world, with $US5 trillion in assets, roughly two-thirds of which is invested in index funds.