Stock returns depend entirely on how the company you invest in performs, its share price movements, and any dividends it pays. There is no guaranteed return, and the value of your investment can go down as well as up. If a company performs poorly or becomes insolvent, you could lose some or all of the money you invested.
A single stock is exposed to that one company's performance: its earnings, management decisions, competitive position, or regulatory changes can move the share price sharply and independently of the wider market. Past performance does not predict future results.
Stocks are generally suited to investors who are comfortable with market risk and have a medium-to-long investment horizon. Only invest money you can afford to leave invested, and consider spreading your investments across several companies and sectors. This is not investment advice.