An index's price can be affected by a range of factors, including: Economic news – investor sentiment, central bank announcements, payroll reports or other economic events can affect underlying volatility, which can cause an index's price to move.

How does news affect market?

More optimistic global news increases stock returns and vice-versa. According to the authors, these effects on stock returns occur mainly through foreign investors rather than local investors. ... Over the long term, optimistic global news attracts permanent inflows and has a stronger impact on returns.

How company news affect stock prices?

The negative news about a company may be reported in the form of a bad earnings report, economic uncertainty, in the long run, failure in corporate governance, and other unfortunate events all translate to the pressure of selling the stocks, resulting in a decrease in stock prices.