How Stocks Work
A stock represents partial ownership in a company. When you buy a share of stock, you become a shareholder — you own a small piece of that business. Companies issue stock to raise capital, and investors buy stock to participate in the company’s growth and profits.
Why Companies Issue Stock
Companies need money to grow — to build factories, hire employees, develop products, or expand into new markets. They have two main options: borrow money (debt financing) or sell ownership stakes (equity financing).
When a company issues stock, it sells shares to investors through an IPO (initial public offering). The company receives the capital, and investors receive ownership shares that they can later trade on a stock exchange. Unlike debt, equity never needs to be repaid — but it does dilute existing owners’ stakes.
What You Get as a Shareholder
| Right | What It Means | Details |
|---|---|---|
| Ownership stake | Proportional claim on assets | Own 100 shares of 1M total = 0.01% of the company |
| Voting rights | Vote on major decisions | Board elections, mergers, executive pay (common stock only) |
| Dividends | Share of profits paid to owners | Not guaranteed — board decides each quarter |
| Capital appreciation | Stock price can increase | Buy at $50, sell at $80 = $30 gain per share |
| Limited liability | You can only lose what you invested | If company goes bankrupt, you lose your shares but not more |
| Residual claim | Last in line in bankruptcy | After bondholders and creditors are paid |
How Stock Prices Are Determined
Stock prices are set by supply and demand. If more people want to buy a stock than sell it, the price goes up. If more want to sell, the price drops. But what drives that demand?
| Factor | How It Affects Price |
|---|---|
| Earnings | Higher profits → higher expected value → price rises |
| Revenue growth | Faster growth → more optimism → price rises |
| Interest rates | Higher rates → future cash flows worth less → price falls |
| Industry trends | Favorable trends lift sector stocks; headwinds drag them down |
| Investor sentiment | Fear pushes prices down; greed pushes them up |
| Macroeconomic data | GDP, inflation, employment shape overall market direction |
In the short term, prices are driven by sentiment and news. Over the long term, they tend to follow fundamentals — earnings, cash flows, and growth. This is the core insight behind fundamental analysis.
How Investors Make Money
There are two ways to profit from stocks:
1. Capital gains: Buy a stock at one price and sell it later at a higher price. If you buy at $100 and sell at $150, your capital gain is $50 per share. Capital gains are taxed — the rate depends on how long you held the stock (long-term vs. short-term).
2. Dividends: Some companies distribute a portion of their profits as dividends. You receive regular cash payments just for holding the stock. Not all companies pay dividends — high-growth companies often reinvest all profits instead. See our dividend investing guide for more.
Total return = capital gains + dividends. Over the long run, dividends have historically contributed roughly 30-40% of total stock market returns.
Types of Stocks
| Type | Key Feature | Example |
|---|---|---|
| Common stock | Voting rights, variable dividends | Most publicly traded shares |
| Preferred stock | Fixed dividends, priority over common | Bank preferred shares |
| Growth stocks | High revenue growth, usually no dividends | Tech companies |
| Value stocks | Undervalued by market, often pay dividends | Established industrials |
| Blue-chip stocks | Large, established, reliable | S&P 500 components |
| Penny stocks | Low price, high risk, low liquidity | Micro-cap companies |
For a detailed breakdown, see Common vs. Preferred Stock and Growth vs. Value Investing.
The Stock Market Ecosystem
Stocks trade on stock exchanges like the NYSE and NASDAQ. Here is how the ecosystem works:
Primary market: A company sells new shares to investors through an IPO. The company receives the money.
Secondary market: Investors trade existing shares among themselves on exchanges. The company does not receive money from these trades — only the sellers do.
Trades are facilitated by brokers (who execute orders on your behalf) and market makers (who provide liquidity by always being willing to buy and sell).
Key Metrics Every Stock Investor Should Know
| Metric | What It Tells You | Learn More |
|---|---|---|
| P/E Ratio | Price relative to earnings — is the stock cheap or expensive? | Valuation Ratios |
| Market Cap | Total value of all shares — company size | Market Cap Guide |
| Dividend Yield | Annual dividend as % of stock price | Dividend Guide |
| EPS | Profit per share | Profitability Ratios |
| Beta | How much the stock moves vs. the market | Risk Measures |
Never evaluate a stock on a single metric. A low P/E ratio might look like a bargain, but if the company has declining revenue and rising debt, it is cheap for a reason. Always combine valuation, growth, profitability, and balance sheet health.
Key Takeaways
- A stock is a share of ownership in a company — you profit through price appreciation and dividends.
- Stock prices are driven by supply and demand, which reflect earnings, interest rates, and investor sentiment.
- Companies issue stock to raise capital without taking on debt.
- Common stockholders have voting rights and upside potential but are last in line in bankruptcy.
- Focus on long-term fundamentals — short-term prices are noisy and sentiment-driven.
Frequently Asked Questions
What happens when you buy a stock?
Your broker sends your order to a stock exchange, where it is matched with a seller. You pay the market price (or your specified limit price), and shares are transferred to your brokerage account. Settlement typically takes one business day (T+1).
Can you lose more money than you invest in stocks?
Not if you buy stocks outright. Your maximum loss is your full investment (if the stock goes to zero). However, if you trade on margin or engage in short selling, losses can exceed your initial investment.
What is the difference between stocks and bonds?
Stocks represent ownership — you share in profits and losses. Bonds represent a loan — you receive fixed interest payments and your principal back at maturity. Stocks have higher return potential but more risk; bonds offer more stability but lower expected returns.
Do all stocks pay dividends?
No. Dividends are optional and decided by the company’s board of directors. Fast-growing companies often reinvest all profits instead of paying dividends. More established, profitable companies are more likely to pay regular dividends.
How do stock prices change after hours?
Stock prices can move during pre-market and after-hours trading sessions. These sessions have lower liquidity and wider bid-ask spreads, so prices can be more volatile. The official opening price the next day may differ from the after-hours close.