The Dow Jones index has doubled between 1991 and 1996 and then again between 1996 and 1999. Furthermore, financial indicators such as the price-earnings ratio and the dividend yield have reached historic records. Many experts claim that the American Stock Exchange is not behaving rationally. A speculative bubble is emerging. Other experts consider that the stock market's behavior can be explained by a change in investors' risk premia.
AFTALION, F. (2000). Exubérance irrationnelle. Le Figaro, pp. 51-51.