In 1993, the first exchange traded fund was launched. At the time, most of Wall Street shrugged. Mutual funds dominated, brokers reigned supreme, and the idea that investors would flock to a new wrapper for index exposure seemed far-fetched. Three decades later, ETFs have reshaped the way the world invests. 15,000 ETFs hold more than $17 trillion in assets globally, power countless retirement portfolios, and are at the very core of financial markets. What began as an experiment is now the default. Today ...