Are the bears coming out of hibernation?

That’s what millions of Americans will be wondering Monday morning when US stocks, rocked last week by the steepest decline in two years, open for trading again.

The Dow Jones industrial average fell 1,096 points last week — or 4.1 percent — climaxed with a hellish 666-point drop on Friday.

It certainly didn’t help matters on Sunday when former Federal Reserve Chair Janet Yellen, on her first day as a private citizen, said stock prices and commercial real estate prices are elevated.

Yellen didn’t say the B-word — bubble — but with investors on edge, maybe she didn’t have to.

“Well, I don’t want to say too high. But I do want to say high,” Yellen said on CBS’ “Sunday Morning” in an interview recorded in her Fed office Friday as she prepared to leave the central bank. “Price-earnings ratios are near the high end of their historical ranges.”

Commercial real estate prices are now “quite high relative to rents,” Yellen said. “Now, is that a bubble or is it too high? And there it’s very hard to tell. But it is a source of some concern that asset valuations are so high.”

Yellen, 71, exited as Fed chief on Feb. 3 after a single four-year term — the shortest tenure of a Fed boss not appointed to a Cabinet post in nearly 70 years.

President Trump opted to replace her with Republican Jerome Powell, who’s been a Fed governor since 2012.

Yellen said she was “disappointed” she wasn’t re-appointed.

“I made it clear that I would be willing to serve, so yes, I do feel a sense of disappointment” about not being renominated, Yellen said. The only woman to serve as the head of the US central bank described her work at the Fed as “the core of my existence.”

Yellen said she’s supportive of former investment banker Powell, 64, whom she termed “thoughtful, balanced, and dedicated to public service.”

The financial system is now “much better capitalized” and the banking system “more resilient” than they were entering the global financial crisis a decade ago, Yellen said.

“What we look at is, if stock prices or asset prices more generally were to fall, what would that mean for the economy as a whole?” Yellen said. “And I think our overall judgment is that, if there were to be a decline in asset valuations, it would not damage unduly the core of our financial system.”

She warned that it would be a “grave mistake” to roll back the regulations put on banks after the previous economic collapse.

The current US economic expansion is now approaching nine years and is the third-longest in duration since 1945.

Yellen said the economy can continue to grow. “Yes, it can keep going,” she said. “Recoveries don’t die of old age.”

With Bloomberg