TQQQ is a levered fund that delivers 3x exposure only over a one-day holding period of NASDAQ-100 stocks. The underlying index includes 100 of the largest non-financial companies listed on NASDAQ based on market capitalization. Historically, technology companies have dominated TQQQs underlying index, so, its future performance might be closely tied to the performance of the tech industry. The fund uses a mathematical approach to determine the type, quantity and mix of investment positions that it believes will produce daily returns consistent with its investment objective. Like many levered products, the fund is not a buy-and-hold ETF as it's a very short-term tactical instrument.