SPY wasn’t just a hit product, it was an inspiration for an entire industry to take off. But it didn’t happen overnight. It took about 10 years for the ETF structure to be utilized for other asset classes and strategies, which today seem normal but at the time were revolutionary.On this installment we look at many of the game changing products that followed, including the first bond ETF, the first gold ETF, Vanguard’s entry and the rise of smart-beta, which was active management’s way to get into the action.