Goldman Sachs Asset Management is making a big bet on defined outcome exchange-traded funds — also known as buffer ETFs, which use options to help protect against market losses.This month, Goldman Sachs agreed to buy defined outcome ETF provider Innovator Capital Management for $2 billion. The deal is expected to close in the first half of next year.Bryon Lake, co-head of the firm's Third-Party Wealth team, expects the funds to be a major growth engine for the industry."We did this deal with Innovator. We'v ...