For every investment you make, there is another one you have overlooked. In other words, you shut yourself to other possibilities by choosing a particular investment line. This is the opportunity cost. Most people reckon with it belatedly after making poor or inferior investment choices. One should take time and even commit resources to educate oneself with regard to any investment choice they intend to make. I believe that everyone of us has instances where the opportunity cost anguished their souls after making a wrong turn.