We talk about  what causes the stock market to go up and down each day. We learn that optimism causes prices to rise. Pessimism causes prices to fall. And that optimism and pessimism can be seen even when no new news about a particular company is released. While daily current news can certainly drive the market up and down, often there is no clear reason for how a company rises or falls on a particular day. Another reason to stay invested for the long term.