You are also free to choose a fund that is based on any index that you want. For example, there are index funds set up for just about every market sector there is — energy, precious metals, banking, emerging markets — you name it. All you have to do is decide that you want to participate, then contribute money and sit back and relax. Your stock portfolio will then be on automatic pilot.
Many people in the investment world also define residual income as revenue stemming from a passive source. This revenue is created without a direct input of effort or time. The investment itself creates addition revenues without having to be managed. Some examples include royalties, dividends, interest, and rent. Take a dividend stock for example. Once the money is invested once, it will keep producing a dividend every year without having to input additional time or resources. This concept is the Holy Grail for most investors.
Residual income is calculated as net income less a charge for the cost of capital. The charge is known as the equity charge and is calculated as the value of equity capital multiplied by the cost of equity or the required rate of return on equity. Given the opportunity cost of equity, a company can have positive net income but negative residual income.