In risk management, the act or strategy of adding more investments to one's portfolio to hedge against the investments already in it. Ideally, this reduces the risk inherent in any one investment, and increases the possibility of making a profit, or at least avoiding a loss. This may also reduce the expected return on a portfolio, but it depends on level and type of diversification. There are two main types of diversification. Horizontal diversification involves investing in similar type investments. Examples include investing in several technology companies or in different types of bonds. Vertical diversification involves investing in very different securities; for example, one may choose to invest in securities traded in different countries, or in both winter clothing and swimsuit companies. Both types of diversification may be as broad or narrow as the investor chooses. In general, the broader the diversification, the less risk and less return. See also: Markowitz Portfolio Theory.