You can only earn so much investing in stocks, and bonds and other such conventional investment methods. However if you are to build wealth and realize its full potential, alternative investments like real estate, or hedge funds are very much helpful. It is a wise thing to invest widely, that way you earn more than if you limited yourself to just one method.
Alternative investments can be describe as physical assets such as estate, cars, company etc. Compare to others like stocks, bonds which are not physical handled. Most investor prefer investing on such this alternative investment because it is physically seen. This investment is the best for investors that fear of risking / loosing his / her money. It is recommended for mostly the fearfully investors.