Us stock 50etf, Nasdaq index etf, s&p etf, etc. According to Cai Xi's survey. ETF is the abbreviation of ExchangeTradedFund, also known as "transactional open index fund" ETF is an open-end stock fund that tracks the market index and can be bought and sold freely at any time in the stock exchange. Domestic US ETF funds include: US 50ETF, Nasdaq Index ETF, S&P ETF, Nasdaq 100ETF, S&P 500ETF, Southern Dow Jones USA Select A, etc. ETF has developed rapidly in the American stock market, with nearly 1000 products and many kinds, such as tracking the American market index, tracking the stock markets of various countries, and tracking different kinds of ETFs such as gold price, oil price and exchange rate.