US office-vacancy rates have hit a new record, surpassing highs set during the 2008 crisis, with further upward pressure expected to follow, according to real-estate services firm Colliers.
"It is not an overly strong economy but also not one where there are clear signs of a recession, or a significant slowdown of any kind is at hand. For equities, I still see an upward tilt for the remainder of the year," Siegel said.
US inflation-adjusted debt yields have hit the highest levels since the 2008-2009 crisis. Rising real yields underscore increasing costs for US borrowers, and add to the investment appeal of bonds versus stocks.