Slow-motion revolution

IN THE past few years, industries including retailing, music and taxis have been spectacularly blown apart by low-cost innovators. Less celebrated is Vanguard, a fund-management group that also fits the disruptive mould. It offers diversified portfolios for retail investors at a fraction of the cost of the industry average, thanks in part to a mutually owned structure that means it cuts fees rather than pays dividends. It now runs more than $3.5 trillion of assets, and takes in another $1 billion or so from investors every working day.