There is no more mistletoe hanging above the markets. : The romance U.S. fund investors once had with the stock market was put to rest in 2018 when buy the dip turned into sell the rip. For evidence, look no further than exchange-traded funds (ETFs), which hold baskets of stocks across the market and have been a primary buyer throughout this bull market. In 2017, investors often added more cash to the funds when the performance sank. Stocks glided higher.