Getty Images ETFs weren’t around on Black Monday.The stock market of 2017 is very different than the market of 1987, when a historic one-day collapse occurred, and one of the biggest changes is the now-ubiquitous presence of ETFs. The rapid growth of exchange-traded funds, which trade like stocks and offer exposure to basically every investible asset class, including major bond categories, commodities, and precious metals, has raised the question of how they might perform and what impact they might have during an intense crash like the one on Oct. 19, 1987,which wiped out 23% in market value in a single day.via