Although markets are deemed efficient in the long run, short-term inefficiencies allow investors to capitalize on anomalies and reap higher rewards that may be out of proportion to the level of risk. Those anomalies are exactly what investors in capital markets try to uncover. Although money markets are considered safe, they have occasionally experienced negative returns. Inadvertent risk, although unusual, highlights the risks inherent in investing - whether long or short term, money markets or capital markets.