Stock Market is never stable

On Monday, the stock market fell sharply that the S&P 500 index fell by 1.97\% and Nasdaq index fell by 2.78%. Apple's shares are traded below $200 per share because Apple's suppliers provided weak outlooks, which let investors believe Apple has reached its peak. Since Apple was the first company to reach one trillion dollar market value, Apple's share price affected the entire stock market, especially the technology companies' share prices. However, is there any actually event that negatively affects the outputs of the industries? The answer is 'no, maybe there is one coming'.

The stock market is built on expectation instead of actual outcomes. Actual outcomes may be important, but if the expectation about the future is perfect enough, investors will choose to ignore the awful output at the moment. Moreover, even if the actual output is brilliant, if the expectation falls, investors' confidence will still be damaged and the stock performance will not improve at all. Overall, actual outcomes at the moment is important because it is a factor that helps investors to make their expectations. Then any factor is important as long as it is relevant to investors' expectations.

Share price is not stable as investors hold different opinions and expectations. If investors were able to be consistent with their expectations, the market will be stable affect the adjustment. However, investors are not consistent, their expectations and opinions are influenced by the market price. Since investors are always changing their expectations and different people hold different opinions, there will not be a stable market price.