When investors and advisors hear the term "arbitrage" they usually think of risk-free profit. True arbitrage, however, is frequently inaccessible to the average investor. Opportunities created by inefficiencies and temporary mispricing usually do not last long. Sophisticated computer trading models, "real time" information exchange and the ability of institutional investors to deploy millions of dollars almost instantly prevent most arbitrage situations from existing for more than a few seconds. Other trading strategies that have come to be called "arbitrage" (e.g., merger arbitrage) are not arbitrage at all because there is risk embedded in the transaction.