How the Stock Market Works and Why People Invest in It
The stock market is where shares of companies change hands between buyers and sellers
The stock market is a system for buying and selling pieces of companies. When you buy a share of stock, you own a small part of that company. If the company does well and grows, your share may become worth more. If the company struggles, your share may lose value. You can sell your shares whenever you want during market hours — usually 9:30 a.m. to 4 p.m. Eastern time on weekdays — and get cash back.
The stock market itself is not a building or a single place. It is a network of exchanges where trades happen. The largest is the New York Stock Exchange (NYSE), where thousands of stocks trade every day. Another major one is the NASDAQ. When you buy a stock, you typically do it through a brokerage account — a company like Fidelity, Charles Schwab, or E*TRADE that holds your money and executes your trades.
Stock prices move based on what buyers and sellers think a company is worth right now. If many people want to buy a stock and few want to sell, the price goes up. If many want to sell and few want to buy, the price goes down. This happens constantly during the trading day, which is why stock prices change minute to minute.
Key Takeaways
- A stock represents ownership in a company, and you buy and sell stocks through a brokerage account during market hours.
- Stock prices rise and fall based on supply and demand — how many people want to buy versus sell at any given moment.
- You make money on stocks in two ways: the price goes up and you sell for more than you paid, or the company pays you a dividend from its profits.
- The stock market is riskier than bonds or savings accounts because prices can drop sharply and you could lose money.
- Most individual investors buy stocks through mutual funds or ETFs rather than picking individual companies themselves.
How you make money from stocks
There are two ways to earn money from owning stock. The first is capital appreciation — the stock price goes up, and you sell it for more than you paid. If you buy 100 shares at $50 each and sell them at $75 each, you make $2,500 before any fees or taxes.
The second way is through dividends. Some companies pay their shareholders a portion of their profits, usually once per quarter. A company might pay $0.50 per share four times a year. If you own 100 shares, you receive $50 each quarter without selling anything. Not all stocks pay dividends — many younger or faster-growing companies reinvest all profits back into the business instead.
Most people who invest in stocks do both: they hold shares hoping the price rises, and they collect dividends along the way. Over long periods — 10 years or more — stocks have historically gone up more often than down, which is why many people use them as part of a retirement plan.
Why stock prices move and what affects them
Stock prices respond to news about the company and the economy. If a company reports strong earnings, the stock often rises. If it announces layoffs or misses its targets, the stock often falls. Broader economic news matters too — if interest rates go up, investors may sell stocks and move money to bonds or savings accounts instead, pushing stock prices down across the board.
Emotion and fear also drive prices. When investors panic and sell, prices can drop quickly even if nothing fundamental about the company has changed. This is called a market correction or bear market if it lasts a while. The opposite happens when optimism spreads and prices rise sharply — a bull market. These swings are normal and have happened many times throughout history.
Individual investors have almost no control over these price movements. You cannot make a stock go up by wanting it to. This is why the stock market is riskier than keeping money in a savings account, where the balance does not move at all.
The difference between picking individual stocks and using funds
You can buy shares of individual companies directly — Apple, Microsoft, Coca-Cola, or thousands of others. This is called stock picking. It requires research: reading financial reports, understanding the business, and watching news about the company. Many people enjoy this, but it takes time and skill to do well.
Most individual investors instead buy mutual funds or ETFs that hold dozens or hundreds of stocks at once. A fund manager or an index formula picks which stocks go in the fund, so you do not have to. You own a small piece of all those companies with one purchase. This spreads your risk — if one company does poorly, it is a small part of your fund. If you picked that one stock directly, you could lose much more.
Funds are simpler for most people because you do not need to research individual companies. You just decide how much risk you want to take and pick a fund that matches that level. A beginner investor often does better with a fund than trying to pick winning stocks.
How much risk you take depends on your time horizon
If you need the money in one or two years, the stock market is not the right place for it. Stock prices can drop sharply in the short term, and you might be forced to sell at a loss if you need cash. Money you need soon belongs in a savings account or a money market fund, where the value does not move.
If you will not need the money for 10 years or longer — such as retirement savings — you can handle short-term drops better. History shows that stocks have always recovered from downturns over long periods. You have time to wait out the bad years and benefit from the good ones. This is why retirement accounts like 401(k)s and IRAs often hold stocks.
Your age matters too. A 25-year-old saving for retirement can afford to take more risk because they have 40 years ahead. A 65-year-old who is about to retire needs to be more careful because they do not have time to recover from a big drop.
What happens when you open a brokerage account
To buy stocks, you need a brokerage account. You open one online with a company like Fidelity, Charles Schwab, E*TRADE, or many others. The process takes about 15 minutes: you provide your name, address, Social Security number, and employment information. The brokerage verifies your identity and then you can fund the account by linking a bank account or transferring money.
Once the account is open and funded, you can search for stocks by company name or ticker symbol (a short code like AAPL for Apple). You enter how many shares you want to buy and at what price, and the brokerage executes the trade. The shares appear in your account, and you own them until you sell.
Most brokerages charge no commission to buy or sell stocks anymore — that changed in the last few years. Some charge small fees for certain services, like financial advice or premium research tools. Read the fee schedule before you open an account so you know what you will pay.
The costs and taxes that affect your returns
When you sell a stock for more than you paid, you owe capital gains tax on the profit. The rate depends on how long you held it. If you held it for more than one year, it is taxed as a long-term capital gain, which has lower tax rates than ordinary income. If you held it for one year or less, it is a short-term capital gain and taxed like regular income — at your normal tax rate, which is usually higher.
Dividends are also taxed, though at lower rates than ordinary income if they are "may have access to dividends" from U.S. companies. You pay tax on dividends in the year you receive them, even if you reinvest them back into the fund.
This is one reason retirement accounts like 401(k)s and IRAs are valuable — you do not pay tax on gains or dividends inside these accounts until you withdraw the money in retirement. That lets your money grow without being eaten away by taxes every year.
Frequently Asked Questions
Can I lose more money than I invested in the stock market?
No. If you buy a stock for $1,000 and it goes to zero, you lose $1,000. You cannot lose more than that. However, if you use borrowed money (called margin) to buy stocks, you can lose more than your initial investment because you owe the borrowed amount back. Most beginners should not use margin.
What is the difference between a stock exchange and a brokerage?
A stock exchange like the NYSE is where trades happen — it is the marketplace. A brokerage like Fidelity is the company that lets you access that marketplace. You open an account with a brokerage, and they route your orders to an exchange to be executed. You never deal with the exchange directly.
How much money do I need to start investing in stocks?
Most brokerages have no minimum to open an account. You can start with $100 or $500 if you want. However, some funds have minimums of $1,000 or more. Check the specific fund or stock you want to buy. Starting small and adding money over time is a common way to begin.
Do I have to watch the stock market every day?
No. If you are investing for the long term, checking prices daily often leads to panic selling when prices drop. Most successful investors check their accounts once a month or once a quarter and do not react to daily price swings. Set a plan and stick to it rather than trading constantly.
What happens to my stocks if the brokerage goes out of business?
Your stocks are protected. Brokerages are required to hold your securities separately from their own assets, and they are insured through the Securities Investor Protection Corporation (SIPC). If a brokerage fails, SIPC ensures you get your stocks or cash back, up to $500,000 per account.