DCA only beats lump sum investing over the long haul in a declining market. i.e.: investing set  amounts monthly in stock XX  at a $10 share would see you acquire more shares if the price went down month over month. In a growing market, you'd be acquiring fewer shares. Because markets increase over time and over the long haul, lump sum investing delivers a greater return than DCA, as mentioned later in the article. But investing a lump at once comes down to timing which of course is tricky.