"Continually lower interest rates and diminishing debt capacity are weighing on consumers' ability and willingness to take on more leverage," Ablin said in a research report.
What to expect if the Fed decides to increase interest rates →
"Certainly, the Nasdaq at 5,000 conjures up images of a tech bubble," said Jack Ablin, chief investment officer at BMO Private Bank. "But we've had time for business profits to grow into those crazy expectations 15 years ago."
Nasdaq closes in on its record high →