What Is a Stock Market?
A stock market is simply a place where buyers and sellers meet to trade shares of companies. Understanding how it works is the first step to understanding every other financial market.
Imagine a massive marketplace — like a farmers market, but instead of vegetables, people are buying and selling tiny ownership stakes in companies. That is essentially what a stock market is. It is an organised, regulated place where shares are traded between buyers and sellers at prices both sides agree on.
Why Does a Stock Market Exist?
It solves two problems at once. Companies need money to grow — to hire people, build factories, launch products. Instead of borrowing from a bank and paying interest, they can sell a piece of themselves to the public. In return, investors get a share of future profits and the ability to sell that stake if they ever need the money back.
A Simple Example
Suppose a company is worth $10 million and needs $2 million to expand. It splits itself into 1 million shares at $10 each and sells 200,000 of them to the public on a stock exchange. Investors who buy those shares now own 20% of the business. If the company grows and becomes worth $20 million, those shares are now worth $20 each — doubling the investor's money.
How Prices Are Set
There is no committee that sets stock prices. Prices are set entirely by supply and demand in real time. If more people want to buy a share than sell it, the price rises. If more people want to sell than buy, the price falls. Every trade that happens is two people agreeing on a price at that exact moment.
Price = Agreement Between a Buyer and a Seller
When you see a stock quoted at $150, it means the last trade happened at $150. The next trade could be higher or lower, depending on who wants to buy or sell next and how urgently.
The Stock Exchange vs the Stock Market
People use these terms interchangeably, but there is a small difference. A stock exchange is the actual venue — the infrastructure and rules that facilitate trading. The stock market is the broader concept of all the buying and selling activity that happens across all exchanges.
| Exchange | Country | Notable listings |
|---|---|---|
| NYSE (New York Stock Exchange) | United States | JPMorgan, Coca-Cola, Nike |
| Nasdaq | United States | Apple, Microsoft, Amazon, Google |
| NSE (National Stock Exchange) | India | Reliance, Infosys, TCS |
| BSE (Bombay Stock Exchange) | India | Oldest in Asia — 5,000+ listed companies |
| LSE (London Stock Exchange) | United Kingdom | Shell, HSBC, BP |
| SSE (Shanghai Stock Exchange) | China | ICBC, PetroChina |
| KRX (Korea Exchange) | South Korea | Samsung, Hyundai |
| Euronext | Europe (multi-country) | LVMH, Airbus, Philips |
How Does an IPO Work?
IPO stands for Initial Public Offering. It is the moment a private company first sells its shares to the public. Before an IPO, ordinary investors cannot buy shares in the company. After the IPO, the shares are listed on an exchange and anyone with a brokerage account can buy or sell them.
After the IPO, the company itself is no longer involved in the trading. When you buy shares on the stock market, you are buying from another investor who is selling — not from the company. The company only received money during the IPO itself.
Where Does a Broker Fit In?
You cannot walk up to the NYSE and start trading. You need a licensed intermediary — a broker. A broker is a company (or app) that holds your money, takes your buy and sell instructions, and routes them to the exchange on your behalf. In India this might be Zerodha or Groww. In the US it could be Robinhood or Charles Schwab. In the UK, Trading 212 or Freetrade.
Regulated and Safe — With Caveats
Stock markets are heavily regulated. Exchanges, brokers, and listed companies must all follow strict rules designed to protect investors. However, regulation protects the process — not your investment decisions. You can still lose money by buying shares that fall in price. The market is fair; it is not forgiving.
Market Hours
Stock markets are only open for trading during certain hours on weekdays. Prices can still move after hours in some markets, but the bulk of trading happens during official session hours.
| Exchange | Trading hours (local time) |
|---|---|
| NYSE / Nasdaq | 9:30 AM – 4:00 PM ET |
| NSE / BSE | 9:15 AM – 3:30 PM IST |
| LSE | 8:00 AM – 4:30 PM GMT |
| KRX | 9:00 AM – 3:30 PM KST |
| SSE | 9:30 AM – 3:00 PM CST |
Markets Are Closed on Weekends and Public Holidays
News events over the weekend — elections, corporate announcements, geopolitical events — cannot be traded until the market opens Monday morning. This is why Monday opens can be volatile: markets are catching up to weekend news all at once.
Key Takeaways
- A stock market is an organised place where shares of publicly listed companies are bought and sold.
- Companies raise money by listing on a stock exchange through an IPO. Investors trade those shares afterwards.
- Price is set by supply and demand — more buyers than sellers pushes prices up; more sellers pushes prices down.
- Major exchanges include NYSE and Nasdaq (US), NSE and BSE (India), LSE (UK), SSE (China), and KRX (Korea).
- You do not trade directly on an exchange — you use a broker who routes your order to the market.