The stock market is where pieces of ownership in companies are bought and sold, helping businesses grow and giving people a chance to invest in their future.

Key idea: The global stock market has grown immensely in value, with a few large exchanges and countries holding most of the market's total worth.

The stock market has grown a lot over the years. In 1980, the total value of all publicly traded stocks worldwide was about 2.5 trillion US dollars. By the end of 2023, this value had jumped to 111 trillion US dollars.

There are about 60 stock exchanges around the world. Out of these, 16 exchanges are very large, each worth 1 trillion dollars or more. These big exchanges make up 87% of the total value of all stocks globally. Most of these large exchanges are in North America, Europe, or Asia.

The United States has the biggest stock market by country, making up about 59.9% of the world's total as of January 2022. Japan is next with about 6.2%, and the United Kingdom follows with about 3.9%.

Key idea: Stock exchanges are organized marketplaces, mostly electronic today, that connect buyers and sellers of stocks, ensuring fair prices and smooth transactions.

A stock exchange is like the central meeting place for buying and selling stocks. It is where stockbrokers and traders come together to make deals. Many big companies list their stocks on an exchange. This makes it easier for people to buy and sell those stocks quickly, which is called being 'liquid.' When a stock is liquid, it is more attractive to investors.

Exchanges can also make sure that trades are completed correctly. Sometimes, stocks are traded 'over the counter' (OTC), which means they are bought and sold directly between two parties without going through a formal exchange. Some large companies list their stocks on exchanges in different countries to attract investors from all over the world.

When you trade in the stock market, you are transferring a stock from a seller to a buyer for money. This only happens when both sides agree on a price. Owning a stock means you own a part of that company.

Anyone can participate in the stock market, from individual people investing small amounts to large organizations like banks, insurance companies, and retirement funds. These large investors might have their buy or sell orders handled by a stock exchange trader.

Historically, some exchanges were physical places where traders would shout out prices to make deals. This was called 'open outcry.' Today, most exchanges use computer networks to make trades electronically. For example, the NASDAQ is an electronic exchange.

When someone wants to buy a stock, they offer a price, called a 'bid.' When someone wants to sell, they ask for a price. A sale happens when a bid and an ask price match. The stock exchange helps to find these matching prices and provides real time information about stocks.

The New York Stock Exchange (NYSE) is a mix of both. It has a physical trading floor, but also allows electronic orders. The NASDAQ, on the other hand, is fully electronic. Its system relies on 'market makers' who always offer to buy and sell certain stocks, ensuring there is always a price available.

People usually prefer to trade on popular exchanges because there are more buyers and sellers, which often leads to better prices. However, there are also other ways to trade outside of exchanges, sometimes to avoid fees.

“A sale happens when a bid and an ask price match.”

Key idea: The stock market involves a wide range of participants, from individual investors to large financial institutions, and saw significant growth after the 2020 pandemic.

Many different kinds of people and groups participate in the stock market. This includes individual people, often called retail investors, who invest their own money. It also includes large organizations, known as institutional investors, such as pension funds, insurance companies, and mutual funds. Even companies themselves can trade their own shares. Recently, automated investment tools called robo-advisors have also become big players, helping individuals invest automatically.

After the 2020 pandemic, participation in the stock market saw a big increase. In 2021, the total value of world stock markets grew by 26.5%, adding 22.3 trillion US dollars. Asia and Oceania held 45% of this global market, Europe had 37%, and America had 16%.

Key idea: Stock market participation is influenced by financial incentives, regional differences, and social factors that make investing more accessible or appealing.

Many things can influence why people and companies choose to participate in the stock market. These include the price of stocks, how the market is rated, and information about how exchanges work. The chance to earn more money compared to other ways of saving is a big draw for individuals to invest.

Where you live can also affect how much people invest. For example, in the United States, participation rates vary a lot from state to state. This suggests that local factors, beyond just the cost of investing, play a role.

Our behavior and social connections also matter. Studies show that people are more likely to invest if their friends or community members also invest. This is because knowledge about how the market works can spread through social networks, making it easier and less intimidating to get involved.

Other factors like a country's economic resources, geography, political stability, and trade policies also influence how much people participate in stock markets.

Key idea: Investment can be direct or indirect, with indirect investment through retirement accounts growing faster due to tax benefits, and participation rates varying significantly by income, wealth, race, and gender.

There are two main ways to invest in stocks: directly or indirectly. Direct investment means you buy shares of a company yourself. Indirect investment means you own shares through something else, like a mutual fund or an exchange traded fund (ETF), which is a collection of many stocks managed by professionals.

From 1992 to 2007, direct ownership of stocks by individuals went up slightly. However, indirect investment through retirement accounts, like 401ks, grew much more. The value of these retirement accounts more than doubled in that time.

One reason for this difference is how taxes work. In the United States, money put into retirement accounts is often taxed only when it is taken out later. But money used to buy stocks directly, and any profits made from them, can be taxed right away. This encourages people to invest indirectly through retirement plans.

Participation in the stock market also varies a lot based on income and wealth. People with higher incomes and more wealth are much more likely to own stocks, both directly and indirectly. For example, in 2007, nearly 90% of the wealthiest households had indirect stock investments, compared to about 10% of the lowest income households.

After the 2008 financial crisis, participation rates for lower income households actually went down, while they slightly increased for the wealthiest households. This shows how economic events can affect different groups differently.

There are also differences in stock ownership based on race and gender. White households are much more likely to own stocks directly than Black or Hispanic households. Similarly, households led by married couples tend to participate more than those led by single men or women.

Key idea: The stock market is vital for economic growth, helping companies raise money, providing liquidity for investors, and serving as an indicator of a country's economic health.

The stock market is very important for several reasons. First, it is a key way for companies to raise money. By selling shares of ownership, businesses can get the money they need to expand, create new products, and hire more people. This is crucial for economic growth.

Second, the stock market provides liquidity for investors. This means that if you own stocks, you can usually sell them quickly and easily to get your money back. This makes investing in stocks attractive compared to things like real estate, which can take a long time to sell.

Third, the stock market is often seen as a sign of a country's economic health. Central banks watch it closely to make sure the financial system is running smoothly, which is part of their job to keep the economy stable.

Exchanges also act as a kind of middleman, making sure that when a stock is sold, the buyer gets the shares and the seller gets paid. This removes the risk that one side might not follow through on the deal. All these activities together help the economy grow by making it easier and less risky for businesses to operate and create jobs.

“The stock market is one of the most important ways for companies to raise money.”

Key idea: Stock prices are affected by economic conditions, inflation, and even psychological factors like group behavior, which can sometimes lead to irrational market movements that challenge traditional theories.

Stock prices are influenced by many things outside of a company, like the overall economy, inflation (when prices go up), and exchange rates. While a company's smart ideas and knowledge (intellectual capital) do not directly affect its current earnings, they can help its stock grow in value over time.

One idea about stock prices is the efficient market hypothesis (EMH). This theory suggests that all available information is already reflected in stock prices. So, it is very hard to consistently 'beat' the market by finding undervalued stocks, because their prices already reflect everything known about them.

However, the 'strong' version of EMH does not fully explain big events like the stock market crash in 1987, when the market dropped dramatically without a clear reason. This shows that prices can fall sharply even when there is no obvious bad news.

A 'softer' version of EMH suggests that while prices might not always be perfectly balanced, investors cannot consistently profit from short term market oddities. Also, while EMH predicts that price movements are mostly random, studies have shown that markets often trend up or down for weeks or longer. This suggests that other factors are at play.

Psychological factors can also lead to exaggerated stock price movements. People tend to see patterns even when there are none, and good news can make investors overly optimistic, driving prices up too much. Also, 'group thinking' can make people follow the crowd, even if it means going against their own judgment. This is like how people prefer to eat at a busy restaurant rather than an empty one, assuming others know best.

Sometimes, the market seems to react in ways that do not make sense to economic news, even if that news should not really change a company's value. However, this might be because the news was already expected, and the market is reacting to whether the news was better or worse than anticipated. Emotions, rumors, and panic can also cause stock prices to swing wildly in the short term.

Key idea: Stock market crashes are sudden, sharp drops in prices often caused by panic and loss of confidence, leading to significant financial losses and prompting measures like circuit breakers to prevent future rapid declines.

A stock market crash is a sudden and sharp drop in stock prices. These crashes often happen due to panic and a loss of confidence among investors. They can also mark the end of speculative bubbles, where stock prices have risen too high too quickly without real company value to support them.

History has seen several famous stock market crashes that caused huge losses. For example, the Wall Street Crash of 1929, which led to the Great Depression, saw the Dow Jones Industrial Average lose 50% of its value. Another major crash was 'Black Monday' in 1987, when the Dow Jones fell by 22.6% in a single day. This crash started in Hong Kong and quickly spread globally.

The 1987 crash was puzzling because there was no clear bad news to explain such a big drop. This made people question some basic ideas about how markets and human behavior work. After this crash, trading was temporarily stopped in some places because computers could not handle the huge number of trades. This allowed central banks to step in and prevent a wider financial crisis.

More recently, the 2008 financial crisis, which started around 2007, caused a widespread decline in markets, including stocks, housing, and lending. The S&P 500 index fell 57% during this time. The 2020 stock market crash was a sudden global event caused by the COVID 19 pandemic, but it ended relatively quickly with new economic measures.

To prevent such rapid declines, many exchanges have put in place 'circuit breakers.' These are automatic systems that halt trading if the market drops by a certain amount in a short period. This gives investors time to calm down and prevents panic selling from spiraling out of control.