Stock prices change every day according to the markets activity. Buyers and sellers cause prices to change and therefore share prices change as a consequence of supply and demand. And its this dance between buyers and sellers, supply and demand that decides how valuable each share is.
If more people want to buy a share than sell it, the price goes up. Conversely, if more people want to sell a share than buy it, theres more supply (sellers) than demand (buyers), and the price goes down.
Shares represent ownership in a company. So even if you own just one single share of a company, you own a part of it no matter how minute. Therefore, the price of a share indicates what investors feel the company is worth.
Stock prices can stay stable for months or fluctualt wildly which is refered to as volatility. There are hundreds of variables that drive stock prices, but the most important one is earnings. Attributable earnings can be described as the profit of a company after taxes and all other deductions i.e. its the net profit.
Theres often the misconception, especially with beginners, that a share that has risen will always fall, or a share that has fallen...