SavingAdvice.com Blog More investors are seeking control and tax benefits of ETFs. And the rising tide of money pouring into ETFs may soon become a tsunami. As a result, you may want to catch the wave. ETFs have been a popular way to invest since their inception in the early 1990s. Today, there are over 7,600 ETFs bulging with trillions of investment dollars. What Is an ETF An ETF (Exchange-Traded Fund) is a security that tracks an index, commodity, bonds, a sector, or other assets. It owns the underlying assets and divides ownership of those assets into shares which investors buy.