A portfolio is a group of stocks, a few or many, owned by an investor. A portfolio of work is the same group of stocks, unless you use the money theory. The purpose of selecting stocks for a portfolio of work is the practice of investing without risking real money.

As a child, you may not have the money to invest. But you can practice the selection of actions and learn to keep track of their investments in the imaginary role. Even if you have money, it's a good idea to go through a learning process before risking their cash. After the drill practice on paper, you are ready to invest.

Select a diversified group of stocks from different sectors to its portfolio fluctuate less and minimize the risk compared with the populations of a single industry. With diversified operations, changes in prices of each stock in a group tend to offset each other, as some up and down. Although the legendary investor, Warren Buffett, lost over $ 200 million equity investment in USAir, still had a good year because diversified. In fact, Peter Lynch was only two years out of their brilliant career of thirteen years since diversified.