Why the 60/40 retirement portfolio needs a revamp

The 60/40 portfolio, stocks to bonds, has long been the tried-and-true method for those building their retirement nest eggs with a safety net of diversification. But times, they are a-changing and BlackRock CEO Larry Fink is advising a makeover. 

"Generations of investors have done well following this approach, owning a mix of the entire market rather than individual securities. But as the global financial system continues to evolve, the classic 60/40 portfolio may no longer fully represent true diversification.