Stock is an investment in a company that gives you part ownership of the business. Companies issue shares of their stock to investors in exchange for capital to help them grow and expand. When the company grows, the value of your stock rises and you can sell it for a profit. Stock is one of the main tools that many people use to build their savings for things like retirement and education. It is important to remember that stocks are not without risk and can lose value, so investing wisely is key.

Buying and selling stocks is done through the stock market, a global network of buyers and sellers. The price of a stock can be affected by a variety of factors, such as supply and demand, the economy and market sentiments. The price of a stock can also be affected by events that affect the company, such as a competitor making a new product that could compete with its own products or bad news about the company from the media.

When a company issues its initial public offering, it sets an IPO price at which it will sell its stock. The money from the sale of the stock goes directly to the company. The price of the stock then fluctuates on the secondary market. This is where the most active trading occurs.

The price of a stock can be influenced by a number of other factors, such as the business forecast for the company and expectations about the company’s sector. It can also be influenced by the stock’s current P/E ratio, which is a comparison of its earnings to its stock price. A high P/E ratio indicates that the stock is overvalued, while a low P/E ratio suggests that the stock is undervalued.

A stock’s price can also be influenced by the amount of cash that is available to buy the stock. This is known as the “intrinsic” value of the stock and can be determined using a variety of models. Most of these models factor in variables that pertain to cash, such as discounted future cash flows and residual income.

Another way to measure a stock’s performance is through a metric called the compound annual growth rate (CAGR), which measures the percentage increase in a stock’s value over a period of time. To calculate this, you need to know the starting and ending prices of a stock at those two points in time. You can find this information on websites such as MarketBeat and through data feeds from brokerages. Once you have this information, you can use a calculator to determine the percentage change in value of a stock over a certain time frame. This calculation is useful for comparing different stocks and investment strategies. It is also a good tool for estimating the total return of a specific investment.