Has Irrational Exuberance return to Markets ?

From the Wikipedia "Irrational exuberance" is a phrase used by former Federal Reserve Board Chairman Alan Greenspan in a speech given at the American Enterprise Institute during the stock market boom of the 1990s. Optimism about jobs data and the bank stress tests, sent Wall Street sharply higher this week. Is this Irrational Exuberance returning to the markets ? Analysts questioned the yardstick, known as Tier 1 common capital, that regulators chose to assess capital levels. The better-known metric called tangible common equity is common yardstick used by most analysts .