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A Brief History of Stock Market_4

Giả sử rằng trước khi những người tham gia thị trường đầu tiên công bố dự kiến sẽ không có sự thay đổi trong tỷ lệ thất nghiệp. Sau đó, những tin tức cho những người tham gia thị trường tài chính rằng nền kinh tế đã làm tốt hơn so với dự kiến . | 62 The Stock Market To explain this we need to ask what investors expected the change in the unemployment rate to be in both instances. Suppose that prior to the first announcement market participants expected no change in the unemployment rate. Then the news to financial market participants was that the economy was doing better than expected. This may translate into greater expected future earnings and stock prices rise. Suppose however that prior to the second announcement investors expected the unemployment rate to fall. If the announced decline is more than expected the news to financial market participants is that the economy may be weaker than anticipated. This may generate revised expectations of future earnings and stock prices fall. What the government told everyone about the economy was the same in both instances but the announced change in the unemployment rate was different from what the market expected. Viewed in this light it is only natural to expect the stock market to behave differently even though the same information was provided. The Role of Expectations The efficient markets view highlights the importance of expectations in explaining stock price changes over time. The basic principle is that what is expected by market participants is largely embedded in current stock prices. For example if everyone expects that a company will announce very strong earnings for the next year market participants act upon what is expected and price this into the current stock price. If the company then announces strong earnings as expected the efficient market hypothesis predicts that the stock price will not change when the earnings are announced. If the actual announcement is that earnings actually are expected to drop this bit of contrary news will cause the stock s price to fall. Since the announcement went against the market s expectation the new information caused the price to react. What happened was not as expected and the stock price adjusted to the new .