Investors have no alternative

So investors, especially those who have retired or are about
to, have no alternative. While Treasury securities are still a haven
for investors because of their low risk of loss or default, they may
not be a safe harbor for those who want an adequate retirement
income. Without adding more risk to your portfolio—even if it is
heavily invested in U.S. stocks—your investment earnings could
just be too low to live on, even if you have done a good job of
saving for retirement.
Adding more than what has been considered normal or average
risk to your portfolio may become so de rigueur that Wall
Street will adjust all its risk-measuring devices to make it appear
that no more than normally needed risk is being taken, even if
many investors say they have no stomach for it. (So-called sophisticated
investors are already doing this, using hedge funds, complex
securities called derivatives, and other similar tools.)