His view that narratives weigh on people's mind differs with experts who believe fundamentals drive the market.
Earlier, Shiller had completely denounced the cryptocurrency market and said that bitcoin was the best example of bubble happening currently
The Yale economist criticized U.S. President Donald Trump during a Saturday interview in Beijing, calling the U.S. commander-in-chief "a showman" who "obviously relishes" celebrity, but acts in a way that's "totally unbecoming for a president."
"That's the sign of the bubble. They're worried but they're thinking they'll get out," he said. "This can suddenly turn, and we're looking somewhat like that now."
The Nobel economics laureate told the Financial Times that his valuation confidence indices, based on investor surveys, showed greater fear that the market was overvalued than at any time since the peak of the dotcom bubble in 2000.
Growth in China has slowed, Roach acknowledged in a CNBC "Squawk Box" interview, "but it's not going in for a crash … and that will present, I think, an opportunity for shares to re-evaluate the China threat, big time."
By summer 2015, China's Securities Regulatory Commission (CSRC) needed them more than ever; a year-long market boom had imploded in a few weeks, and the government was desperate to keep the crisis from widening.
Shiller highlighted worrying signs from the cyclically adjusted price-earnings ratio (CAPE) ratio - a stock price measure he helped create, which measures the S&P 500's average inflation-adjusted earnings over the previous 10 years.
Carl Icahn, Jeremy Grantham, John Hussman. This is not a list of one of the top money managers of the world. These are investors who have recently warned of an impending stock collapse, predicated upon their expectations of a major economic downturn.
Robert Shiller, who won the esteemed award with two other Americans for research into market prices and asset bubbles, pinpointed the US stock market and Brazilian property market as areas of concern.
Robert Shiller, who shared the 8 million Swedish crown (USD 1.25 million) prize with fellow laureates Eugene Fama and Lars Peter Hansen, said the US Federal Reserve's economic stimulus and growing market speculation were creating a 'bubbly' property boom.
Recent housing and employment data suggests the US economy is at a tipping point where a double-dip recession is possible and home prices could have much further to fall, a veteran economist said on Thursday.