Irrational exuberance

I had come across the term ‘irrational exuberance’ many a times in newspapers and magazines in recent times. Today I decided to look up what it means.
The Oxford dictionary defines “irrational” as ‘without reason’ and “exuberance” as ‘full of high spirits or growing profusely.’

Origin of the term
The term "irrational exuberance" derives from some words that Alan Greenspan, former chairman of the Federal Reserve Board in Washington, used in a black-tie dinner speech entitled "The Challenge of Central Banking in a Democratic Society" before the American Enterprise Institute at the Washington Hilton Hotel December 5, 1996.
Fourteen pages into this long speech, which was televised live on C-SPAN, he posed a rhetorical question: "But how do we know when irrational exuberance has unduly escalated asset values, which then become subject to unexpected and prolonged contractions as they have in Japan over the past decade?" He added that "We as central bankers need not be concerned if a collapsing financial asset bubble does not threaten to impair the real economy, its production, jobs and price stability."
Immediately after he said this, the stock market in Tokyo, which was open as he gave this speech, fell sharply, and closed down 3%. Hong Kong fell 3%. Then markets in Frankfurt and London fell 4%. The stock market in the US fell 2% at the open of trade. The strong reaction of the markets to Greenspan's seemingly harmless question was widely noted, and made the term irrational exuberance famous.

In the limelight
In the year 2000, Robert J. Shiller authored a book titled “Irrational exuberance”. It was about the society’s obsession with the stock market and how it fuelled volatility in the financial markets. He said the people were infatuated with the stock markets and had forgotten about the potential of real assets, such as income from our livelihoods and homes.
In recent times, the newspapers and magazines have repeatedly been using this term when writing about the stock markets, especially regarding its volatility. I have seen it in The Hindu Business Line and Frontline in recent years.

Is it significant?
I feel it’s the apt word for the recent volatility in the stock markets. It tells us the reason for the increased presence of volatility in the markets and it’s not because of important changes in the economy or the company that the share prices fluctuate. Market news and sentiments of the people affect the market too. Neither should a market with strong fundamentals nor investors who have fundamentals resort to irrational behaviour.