Still, while these and other academic advancements have greatly improved the day-to-day operations of the financial markets, history is rife with examples that seem to contradict the notion that finance behaves according to rational scientific laws. For example, stock market disasters, such as the October 1987 crash (Black Monday), which saw the Dow Jones Industrial Average (DJIA) fall 22%, and the great 1929 stock market crash beginning on Black Thursday (Oct. 24, 1929), are not suitably explained by scientific theories such as the EMH. The human element of fear also played a part (the reason a dramatic fall in the stock market is often called a “panic”).
In addition, the track records of investors have shown that markets are not entirely efficient and, therefore, not entirely scientific. Studies have shown that investor sentiment appears to be mildly influenced by weather, with the overall market generally becoming more bullish when the weather is predominantly sunny. Other phenomena include the January effect, the pattern of stock prices falling near the end of one calendar year and rising at the beginning of the next.