Portfolio management if one of the costliest mistakes that investors make. Imagine a portfolio as a forest, and the stocks would be trees. Investors tend to focus a lot more on the individual trees that they forget about the forest. In a diversified portfolio, one tree is not as important when compared to the forest. A stock that has made 50% does not mean much, because the portfolio of stocks can still lose money as a whole despite the one big gain in a stock. A good gardener would understand portfolio management easily. His aim is to maintain a nice looking garden. It would be a garden with blooming flowers and scent abound. To achieve that, he would have to do two main tasks; one, to rid the weeds and second, to fertilize and water the garden to keep the flowers growing. That is exactly what an investor should do with his portfolio ......