Stock Market Basics

The stock market is a collection of exchanges where shares of publicly traded companies are bought and sold. The two largest U.S. exchanges are the New York Stock Exchange (NYSE) and NASDAQ. When you buy a stock, you are purchasing a small ownership stake in a real business. The stock market allows companies to raise capital by selling shares to the public, and it allows investors to participate in the growth of those companies over time. The U.S. stock market has returned roughly 10% annually on average over the past century.

You can start with as little as $1. Most major brokerages — Fidelity, Charles Schwab, Vanguard, and Interactive Brokers — have eliminated account minimums entirely. Fractional share investing means you can buy a piece of a $500 stock for just $5. The amount matters far less than building the habit of investing consistently. Someone who invests $50 per month starting at age 25 will have substantially more at retirement than someone who waits until 35 to invest $200 per month.

The NYSE (New York Stock Exchange) is the world's largest stock exchange by market capitalization. It was founded in 1792 and historically used a physical trading floor with human specialists. NASDAQ, founded in 1971, was the world's first electronic exchange and has always been fully computerized. Today both exchanges are mostly electronic. NYSE tends to list more established, traditional companies (e.g., Berkshire Hathaway, Walmart, JPMorgan), while NASDAQ is known for technology companies (e.g., Apple, Microsoft, Amazon). As an investor, the exchange a stock trades on has minimal impact on your experience — you buy and sell through your brokerage regardless.

The price-to-earnings (P/E) ratio is the most common metric for evaluating whether a stock is expensive or cheap relative to its earnings. It is calculated by dividing the stock price by the company's earnings per share (EPS). A P/E of 20 means you are paying $20 for every $1 of annual earnings. The S&P 500's historical average P/E is roughly 15-17. A higher P/E suggests investors expect faster future growth; a lower P/E might indicate the market views the company as having slower growth prospects, or it could signal an undervalued opportunity. P/E is a starting point, not a complete picture — always look at growth rate, debt, and competitive position alongside it.

Start with index funds. About 90% of professional fund managers fail to beat the S&P 500 over a 15-year period, and they do this full time with teams of analysts. Individual stock picking requires hundreds of hours of research, the emotional discipline to hold through 30-50% drawdowns, and the honesty to admit when your thesis is wrong. An S&P 500 index fund (like VOO or FXAIX) gives you instant diversification across 500 companies for an expense ratio of 0.03%. If you want to pick individual stocks, limit it to 5-10% of your portfolio until you have years of experience.

A dividend is a cash payment a company makes to its shareholders, typically quarterly, as a way of sharing its profits. Not all companies pay dividends — fast-growing tech companies often reinvest all profits back into the business. Established, profitable companies like Johnson & Johnson, Coca-Cola, and Procter & Gamble have paid increasing dividends for 50+ consecutive years (these are called Dividend Aristocrats). The S&P 500's average dividend yield is roughly 1.3-1.5%. You can reinvest dividends automatically to buy more shares (called DRIP), which significantly compounds your returns over time. About 40% of the S&P 500's total return since 1930 has come from reinvested dividends.

A market order buys or sells a stock immediately at the best available price. You are guaranteed execution but not the exact price. A limit order lets you set the maximum price you will pay (when buying) or the minimum price you will accept (when selling). Limit orders give you price control but are not guaranteed to execute if the stock never reaches your specified price. For beginners buying ETFs or large-cap stocks, market orders during regular trading hours are fine — the bid-ask spread is typically pennies. For less liquid stocks or volatile conditions, limit orders protect you from unexpected price swings.

A bull market is a sustained period when stock prices are rising, generally defined as a 20% or greater increase from a recent low. A bear market is the opposite — a 20% or greater decline from a recent high. Since 1950, the average bull market has lasted about 4.4 years with an average gain of 154%. The average bear market has lasted about 11.3 months with an average decline of 32%. Bear markets feel terrifying but are normal and relatively short-lived. The key insight: every bear market in history has eventually been followed by a bull market that recovered all losses and then some. Staying invested through both is the single most important thing you can do.