Make more of your money by comparing accounts for investing, trading & currency transfers. In this guide, we take a look at the pros and cons of drip-feeding versus lump-sum investing. Buy low and sell high is said to be the secret to successful investing, but with even the most experienced of investors struggling to predict market movements, it’s a strategy that is fraught with risks. The difficulty is there is no real way of figuring out how low is low and how high is high.