When people hear that the stock market went up or down, they often imagine a single marketplace where investors buy and sell shares of companies.
That is partly correct. However, the stock market is more complex than that.
Every trading day, millions of investors, financial institutions, pension funds, mutual funds, and other market participants buy and sell ownership interests in publicly traded companies. Their decisions collectively determine the prices of stocks.
For someone new to investing, the process can seem confusing.
Who determines stock prices? Where does the money go when someone buys a stock? Why do companies issue shares? And why can stock prices change dramatically even when the underlying businesses have changed very little?
Understanding these questions is an important first step toward becoming a more informed investor.
In this guide, we will explain how the stock market works, who participates in it, how stock prices are determined, and how investors can distinguish between short-term market movements and long-term business value.
Educational Disclaimer: This article is for educational purposes only and does not constitute personalized investment advice.
What Is the Stock Market?
The stock market is a system of exchanges, brokers, and electronic trading networks where investors buy and sell ownership shares in publicly traded companies.
A stock represents an ownership interest in a corporation. When you purchase a share of stock, you become a shareholder and own a small portion of that business.
The stock market provides two important economic functions:
- It helps companies raise capital from investors.
- It allows investors to buy and sell existing shares, providing liquidity.
These functions operate through two interconnected markets: the primary market and the secondary market.
Understanding the difference is essential to understanding how the stock market actually works.
Why Do Companies Issue Stock?
Businesses need capital to operate and grow.
A company may need money to:
- Build factories or distribution centers
- Develop new products
- Purchase equipment
- Hire employees
- Expand into new markets
- Acquire other businesses
- Strengthen its balance sheet
Companies can finance these activities through internally generated cash flow, borrowing, or issuing equity.
When a company issues stock, it sells ownership interests to investors in exchange for capital.
Unlike debt financing, common stock generally does not require scheduled interest payments or repayment of principal. However, issuing additional shares can dilute the ownership percentage of existing shareholders.
What Is an Initial Public Offering (IPO)?
An initial public offering (IPO) is the process through which a private company first offers its shares to public investors.
Before an IPO, ownership is generally concentrated among founders, employees, venture capital firms, private equity investors, or other private shareholders.
An IPO allows shares to become publicly traded. The company typically works with investment banks and other advisers to determine the offering structure, pricing, and distribution of shares.
Importantly, not every IPO dollar necessarily goes to the company. Some offerings include existing shareholders selling their own shares.
The distinction depends on whether the shares being sold are newly issued by the company or existing shares held by current owners.
Primary Market vs. Secondary Market
The stock market consists of two closely related markets.
The Primary Market
The primary market is where companies issue new securities to raise capital.
For example, suppose a company issues 10 million new shares at $20 per share.
The company raises:
10,000,000 shares × $20 = $200,000,000
Ignoring underwriting fees and other transaction expenses, the company receives $200 million.
The investors receive newly issued shares in exchange.
The Secondary Market
The secondary market is where investors trade shares that have already been issued.
Suppose an investor purchases 100 shares of a company through a brokerage account.
In an ordinary secondary-market transaction, the money goes to the seller of those shares, not directly to the company.
The company does not receive new capital simply because its shares trade between investors.
However, a functioning secondary market benefits companies indirectly by making their shares easier to buy and sell. This liquidity can make investors more willing to provide capital in future offerings.
The key distinction: The primary market helps companies raise capital. The secondary market allows investors to trade ownership interests.
What Is a Stock Exchange?
A stock exchange is an organized marketplace where securities are traded under established rules.
Two of the best-known stock exchanges in the United States are the New York Stock Exchange (NYSE) and Nasdaq.
New York Stock Exchange (NYSE)
The New York Stock Exchange is one of the world’s largest stock exchanges and lists many established American and international corporations.
The NYSE is famous for its trading floor on Wall Street in New York City. However, most trading activity today is conducted electronically.
Nasdaq
Nasdaq is an electronic stock exchange known for listing many technology companies, along with businesses from numerous other industries.
Companies such as Apple, Microsoft, and Nvidia are listed on Nasdaq.
Although the NYSE and Nasdaq have different market structures, both facilitate trading in publicly listed securities.
Trading also occurs through other exchanges and alternative trading venues.
The stock market is therefore not one physical location. It is a connected financial system.
How Do Investors Buy and Sell Stocks?
Most individual investors access the stock market through a brokerage account.
A brokerage firm acts as an intermediary between the investor and the markets where securities are traded.
A typical transaction follows five steps.
Step 1: The Investor Submits an Order
The investor chooses a stock, the number of shares, and the type of order.
Step 2: The Broker Routes the Order
The brokerage sends the order to an exchange, market maker, or another execution venue.
Step 3: The Order Is Executed
The order is matched with available buying or selling interest, subject to the order’s conditions.
Step 4: The Trade Is Confirmed
The brokerage reports the execution price and number of shares.
Step 5: The Trade Settles
Securities and cash are delivered through the clearing and settlement system.
In the United States, most regular-way stock transactions settle one business day after the trade date, a convention known as T+1 settlement.
Market Orders vs. Limit Orders
Two common order types are market orders and limit orders.
A market order seeks immediate execution at the best available prices.
The main advantage is that it generally prioritizes execution.
However, the final execution price is not guaranteed.
A limit order specifies the maximum price an investor is willing to pay when buying, or the minimum price the investor is willing to accept when selling.
For example, an investor might place a limit order to purchase shares at $50 or less.
If no seller is willing to transact at that price, the order may remain unfilled.
A limit order provides greater control over price, but execution is not guaranteed.
How Are Stock Prices Determined?
Stock prices are determined through the interaction of buyers and sellers in the market.
Every trading day, investors submit orders expressing the prices at which they are willing to buy or sell shares.
When compatible orders meet, a trade can occur.
The price of the most recent transaction is often reported as the stock’s current market price.
Understanding the Bid and Ask
The bid is the highest displayed price a buyer is currently willing to pay.
The ask is the lowest displayed price a seller is currently willing to accept.
The difference between them is called the bid-ask spread.
Suppose a stock has the following quoted prices:
- Bid price: $49.98
- Ask price: $50.02
The bid-ask spread is:
$50.02 − $49.98 = $0.04
In this example, the spread is four cents per share.
Stocks with substantial trading activity often have narrow bid-ask spreads. Less liquid stocks may have wider spreads, increasing the cost of trading.
Why Do Stock Prices Move?
Prices change as investors revise what they are willing to pay or accept.
Factors influencing those decisions include:
- Company earnings
- Revenue growth
- Profit margins
- Interest rates
- Economic conditions
- Industry developments
- Competitive threats
- Management decisions
- Investor expectations
- Market sentiment
The important point is that a stock price reflects transactions among market participants, not an official determination of what a company is worth.
Who Participates in the Stock Market?
The stock market brings together participants with different goals, strategies, and time horizons.
Individual Investors
Individual investors buy shares for long-term ownership, income, retirement planning, or shorter-term trading.
Institutional Investors
Institutional investors manage money on behalf of other people or organizations.
Examples include mutual funds, pension funds, insurance companies, endowments, and investment managers.
Exchange-Traded Funds and Index Funds
Funds pool investor capital and hold portfolios of securities.
Index funds generally seek to track a specified market index rather than select individual stocks based on fundamental analysis.
Traders
Some participants focus on shorter-term price movements.
Their strategies may involve momentum, statistical relationships, market liquidity, or other trading signals.
Market Makers
Market makers provide buying and selling quotations and help facilitate trading.
They play an important role in market liquidity, although they also manage inventory and execution risks.
These participants may value the same stock differently because they have different expectations, constraints, and investment horizons.
What Is a Stock Market Index?
A stock market index measures the performance of a defined group of securities according to a specified methodology.
An index provides a convenient way to describe market performance without examining every stock individually.
Three widely followed U.S. stock indexes are the S&P 500, Dow Jones Industrial Average, and Nasdaq Composite.
S&P 500
The S&P 500 tracks approximately 500 leading U.S. companies.
It is widely used as a benchmark for large-cap U.S. equities.
The index is weighted by float-adjusted market capitalization, meaning larger companies generally have a greater influence on its performance.
Dow Jones Industrial Average
The Dow Jones Industrial Average tracks 30 established U.S. companies.
Unlike the S&P 500, it uses a price-weighted methodology.
This means that companies with higher share prices generally have greater influence on the index, subject to its divisor adjustments.
Nasdaq Composite
The Nasdaq Composite includes thousands of Nasdaq-listed securities.
It has substantial exposure to technology-oriented businesses.
When financial news reports that the stock market rose or fell, it is often referring to the performance of one or more of these indexes.
However, an index is not the same thing as the entire market.
A rising S&P 500 does not mean every company in the index increased in price.
What Is Market Capitalization?
Market capitalization, often called market cap, is the total market value of a company’s outstanding common shares.
The basic formula is:
Market Capitalization = Share Price × Shares Outstanding
Suppose a company has:
- 100 million shares outstanding
- A current share price of $50
Its market capitalization would be:
100,000,000 shares × $50 = $5,000,000,000
The company has a market capitalization of $5 billion.
Market capitalization is an equity valuation measure.
It is not the same as enterprise value, which also considers debt, cash, and other relevant claims.
Does a Rising Stock Price Make a Company Richer?
Not directly.
When existing shares rise in the secondary market, the company does not automatically receive cash. Instead, the market value of shareholders’ ownership interests increases.
A higher share price can still benefit a company indirectly.
For example, it may allow the company to raise additional equity capital on more favorable terms or use shares as consideration in an acquisition.
What Is the Difference Between Stock Price and Intrinsic Value?
This is one of the most important distinctions in fundamental investing.
Stock price is what investors are currently paying for a share. Intrinsic value is an estimate of what the underlying business is economically worth.
Stock prices are observable.
Intrinsic value must be estimated.
Investors may estimate intrinsic value by examining:
- Revenue
- Profitability
- Free cash flow
- Growth opportunities
- Competitive advantages
- Capital requirements
- Financial risk
- Discount rates
Two investors can examine the same company and arrive at different intrinsic value estimates.
That uncertainty is part of investing.
A Simple Intrinsic Value Example
Suppose a company trades at $40 per share.
After analyzing the business, an investor estimates that the stock’s intrinsic value is approximately $50.
The difference is:
$50 − $40 = $10
Relative to the estimated intrinsic value, the stock trades at a 20% discount.
($50 − $40) ÷ $50 × 100 = 20%
However, the $50 estimate is not guaranteed to be correct.
It depends on assumptions about future business performance, risks, and valuation.
A stock trading below estimated intrinsic value may offer an opportunity, but only if the analysis is sound and the risks are adequately understood.
Why Can Stock Prices Move Even When a Business Has Not Changed?
Stock prices respond not only to current business results but also to expectations about the future.
Consider a company expected to earn $5 per share next year.
If investors become more optimistic about future growth, they may be willing to pay a higher multiple of those earnings.
Alternatively, if interest rates rise, investors may demand higher returns and become less willing to pay high valuations for future earnings.
In both cases, the stock price can change without an immediate change in the company’s current operating results.
Earnings and Valuation Multiples
A simple way to illustrate this is through the price-to-earnings ratio.
P/E Ratio = Share Price ÷ Earnings Per Share
Suppose a company earns $5 per share.
At different P/E ratios, the implied share price would be:
- 10× earnings: $50 per share
- 15× earnings: $75 per share
- 20× earnings: $100 per share
- 25× earnings: $125 per share
Even with unchanged earnings, the stock price can vary substantially depending on the valuation multiple investors are willing to pay.
This is one reason stock prices can be volatile.
What Causes Stock Market Crashes and Corrections?
A stock market correction is commonly described as a decline of at least 10% from a recent high.
A bear market is commonly described as a decline of at least 20%.
These are market conventions rather than strict economic laws.
Large declines can result from several factors, including:
- Economic recessions
- Financial crises
- Rising interest rates
- Falling corporate earnings
- Excessive prior valuations
- Credit-market stress
- Sudden changes in investor expectations
Market declines can also become self-reinforcing.
When prices fall, some investors sell to reduce risk or meet liquidity needs. Additional selling can put further pressure on prices.
However, a falling stock market does not mean every underlying business has deteriorated by the same percentage.
This distinction is important for long-term investors.
What Happens When You Own a Stock?
Owning common stock gives an investor an economic interest in a corporation.
Depending on the company’s share structure, common shareholders may have rights such as:
- Voting on certain corporate matters
- Receiving dividends when declared
- Participating in the company’s residual economic value
- Selling their shares to another investor
Common shareholders are residual claimants.
If a company is liquidated, creditors and other senior claimants generally have priority over common shareholders.
That is one reason stocks carry more risk than many forms of corporate debt.
How Do Shareholders Make Money?
There are two primary sources of shareholder returns.
Capital Appreciation
Capital appreciation occurs when the market price of shares increases.
Dividends are distributions of capital made by a company to its shareholders.
For example, suppose an investor purchases a stock for $50, receives $2 in dividends during the year, and sells the stock for $55.
The investor’s total return, before taxes and trading costs, is:
($55 − $50 + $2) ÷ $50 × 100 = 14%
The total return is 14%.
However, dividends are not guaranteed, and stock prices can decline.
What Is the Difference Between Investing and Speculation?
Investing and speculation can involve purchasing the same securities.
The distinction often lies in the investor’s reasoning and time horizon.
A fundamental investor generally focuses on:
- The underlying business
- Future cash flows
- Competitive position
- Financial strength
- Management
- Valuation
A speculator may focus more heavily on expected price movements, trading patterns, momentum, or changes in market sentiment.
These approaches are not always mutually exclusive, and the distinction is not defined by holding period alone.
A long holding period does not automatically make a decision an investment.
Likewise, selling a stock after a short period does not necessarily make the original decision speculative.
What matters is the underlying analysis and the basis for the expected return.
Why Does the Stock Market Matter to the Economy?
The stock market supports economic activity in several ways.
Capital Formation
Public equity markets allow companies to raise capital from a broad base of investors.
Liquidity
Investors can generally sell publicly traded shares without requiring the company to repurchase them.
Price Discovery
Market trading continuously incorporates new information into securities prices.
Risk Sharing
Public ownership allows business risks and potential returns to be distributed among many investors.
Household Wealth
Stocks are an important component of retirement accounts, pension portfolios, and long-term savings.
However, stock market performance and economic performance are not identical.
Stock prices are forward-looking and reflect expectations, while many economic indicators describe activity that has already occurred.
How Does the Stock Market Connect to Fundamental Investing?
The stock market provides a mechanism for buying and selling shares.
Fundamental investing provides a framework for deciding what those shares may be worth.
The two are related, but they answer different questions.
The market answers:
What price are buyers and sellers currently willing to accept?
Fundamental analysis asks:
What is the underlying business worth based on its economics and expected future cash flows?
A fundamental investor may study a company for weeks before deciding whether its stock price offers an attractive opportunity.
That research often involves understanding the business model, evaluating financial statements, assessing competitive advantages, analyzing management, and estimating intrinsic value.
The goal is not to predict every daily price movement.
It is to make informed decisions about business ownership.
How to Begin Understanding Stocks as a Fundamental Investor
For someone new to investing, a useful approach is to work through the following process.
Step 1: Understand the Business
Learn how the company makes money, who its customers are, and what products or services it provides.
Step 2: Study the Industry
Identify competitors, barriers to entry, customer bargaining power, and important industry trends.
Step 3: Read the Financial Statements
Examine revenue, profits, assets, liabilities, cash flow, and capital requirements.
Step 4: Evaluate Business Quality
Consider profitability, return on invested capital, pricing power, and competitive advantages.
Step 5: Assess Management
Examine capital allocation, incentives, communication, and long-term decision-making.
Step 6: Estimate Value
Use appropriate valuation methods to develop a reasonable range of intrinsic values.
Step 7: Compare Price With Value
Consider the uncertainty of your estimates and whether the market price provides an adequate margin of safety.
This process does not eliminate investment risk.
It does, however, shift attention away from daily market noise and toward the economics of the underlying business.
Common Stock Market Misconceptions
A Stock Price Tells You What a Business Is Worth
A stock price tells you what shares are trading for, not necessarily their intrinsic value.
A Low Share Price Means a Stock Is Cheap
A $10 stock is not automatically cheaper than a $200 stock.
The number of shares outstanding, earnings, cash flow, debt, and business value all matter.
Companies Receive Money Every Time Their Stock Trades
Most ordinary stock transactions occur between investors in the secondary market.
The company generally does not receive proceeds from those transactions.
The Stock Market Always Reflects Current Economic Conditions
Stock prices reflect expectations about the future and can move ahead of economic data.
A Great Company Is Always a Great Investment
A strong business can be a disappointing investment if purchased at an excessively high price.
Market Declines Mean Investors Should Automatically Sell
A market decline is not, by itself, a complete investment thesis.
Investors should examine changes in business value, risk, and their own financial circumstances.
Key Takeaways
- The stock market is a system through which investors buy and sell ownership interests in publicly traded companies.
- Companies raise equity capital through the primary market, while investors trade existing shares through the secondary market.
- Stock exchanges and electronic trading networks facilitate transactions between market participants.
- Stock prices are determined by buyers and sellers through market trading.
- Brokerage firms provide access to stock trading, while clearing and settlement systems complete transactions.
- Market capitalization measures the market value of a company’s outstanding common shares.
- Stock market indexes measure the performance of selected groups of securities.
- Stock prices can change because of earnings, interest rates, expectations, and investor sentiment.
- Market price and intrinsic value are different concepts.
- Fundamental investing focuses on the underlying business rather than attempting to predict every short-term market movement.
Final Thoughts
The stock market is often presented as a collection of constantly changing prices. That is what investors see on financial websites, brokerage platforms, and television.
However, behind every stock is an actual business.
Those businesses employ people, serve customers, purchase equipment, develop products, compete for market share, and generate cash flow.
The stock market provides a mechanism for transferring ownership of those businesses between investors.
Understanding how the market operates is useful. Understanding what the underlying businesses are worth is even more important.
For fundamental investors, the objective is not simply to participate in market activity. It is to make intelligent decisions about business ownership based on sound analysis and reasonable valuations.
Continue Your Learning
What Is Fundamental Investing?
- Learn the core principles behind evaluating businesses, understanding intrinsic value, and making disciplined long-term investment decisions.
- Learn where to find important information about a company’s operations, risks, financial performance, and management.
What Makes a Great Business Model?
- Explore the economic characteristics that can help a company generate durable profits and long-term value.
- Understand how investors estimate business value independently of current stock prices.
- Explore the distinction between business-focused analysis and trading based primarily on expected price movements.
Fundamental Investing Foundations
- For a more structured introduction to investing, explore FII’s beginner-oriented course.