Stocks can appreciate in value as profits are earned and future expectations for growth are positive. Stocks can also depreciate in value if the company suffers losses or, in the extreme, goes bankrupt. Dividends may also increase or decrease. The stock market itself also affects the value of stocks. Stocks have no maturity or expiration date, nor are there guarantees to repay your investment or to pay dividends.
Shareholders share in the fortunes, good and bad, of the company.
Stock values also fluctuate with the general economy, with changes in the industry of which the company is a part, and with perceived changes in the future of the company. However, if the company thrives and makes a profit, so does the investor. Most individual stockholders own only a small fraction of a company. Stockholders may or may not receive a stock certificate as evidence of ownership. Ownership information may be kept on computer files, rather than via printed stock certificates.