Research from Merrill Lynch , for example, found that growth stocks outperform during periods of falling interest rates. Dollar-cost averaging is a wise choice for most investors. So if you pick the wrong stock, it could become worthless. To repeat the first point of this article. Why invest? Either way, funds allow investors to access a diversified set of growth stocks, reducing the risks of any single stock doing poorly and ruining their portfolio. Putting DCA to work means deciding on three parameters:.