"The nutshell is this: the old line economy stocks just don’t work because they have earnings and eventually rising interest rates impact earnings. New economy stocks have no earnings, so investors don’t see a need to exit.
Your investment strategy must account for the truth that there are going to be large drops in every asset class and that “diversification” alone is not enough.
In the market environment of the past several years "everyone is a genius." However, we are headed for a possible sequel of 2008, largely because of debt and stratospheric overvaluations in almost every asset class. Rising deficits and increasing rates all while further loading up on systemic debt while at the very top of the business cycle will likely have global repercussions in the non-too-distant future.