"[P]ortfolios overly weighted in 'safe' investments are likely to exhaust their assets well before today's life expectancy.... [A] portfolio invested in 100% fixed or short term vehicles would be exhausted within 25 years base on a 5% draw down rate; whereas a portfolio with just 20% allocated in stocks would last another five years. A properly diversified portfolio of 50% stocks, 40% bonds and 10% in short term vehicles, would last indefinitely."