Why do share price go up and down?

Question

I was looking at google finance, price go up and down, what's happening at that time? Also how do you know if someone is selling or buying?

Answer 1

because peoples valuation of the company changes when something happens for example airline companies are affected by oil prices so they have to put the price up and less customer can fly therfore that companies shares will go down. etc.etc

hope this helped

Answer 2

The share prices go up and down as they depend on what the market thinks they are worth. If a company has great earnings then chances are the market will think its worth more. If they disappoint chances are the share price will drop unless the market sees forward earnings will be better.

The sector the stock is in also plays a large part. When no one wanted to buy bank stocks most of the banking shares tanked. When everyone was buying anything to do with oil almost all the companies in the sector moved up.  

Answer 3

supply and demand rule

Answer 4

Shares are usually traded in blocks of shares and there is usually a stockbroker that determines the fair value of a companies share at any given time.  Most of the times mutual funds are the biggest buyers/sellers of stocks so often they have the most influence on stock price.