NerdWallet-ETF Holdings

FILE - This Thursday, Feb. 9, 2017, file photo, shows the floor of the New York Stock Exchange. Exchange-traded funds have swept the stock market over the past decade and been a blessing for many investors. But while large index-based funds, such as those that track the Standard & Poor’s 500, may fairly represent the index’s stocks, smaller niche ETFs don't always deliver strictly what their names promise, and you might wind up indirectly buying a lot of something you didn’t really want. (AP Photo/Mark Lennihan, File)