For many people, the stock market is still an abstract concept associated with news headlines that go up or down without really understanding why. Understanding how it works at a basic level is the first step before considering investing in it.
What the stock market is
The stock market is an organized market where shares of listed companies are bought and sold — that is, companies that have decided to open part of their capital to outside investors in exchange for funding, allowing anyone to become a part-owner of a small slice of those companies.
How a stock's price is formed
A stock's price is determined by supply and demand at any given moment: if more investors want to buy than sell at a given price, the price tends to rise; if the opposite happens, it tends to fall. That price reflects, in theory, the market's collective expectations about that company's future value, although in the short term it can deviate considerably due to emotional or short-term factors.
What a stock index is
A stock index (such as Spain's IBEX 35, or the S&P 500 in the United States) is a figure that summarizes the combined performance of a specific group of listed companies, calculated using a formula that weights each company according to various criteria (typically its market capitalization). It serves as a general thermometer of how that particular market or sector is performing.
Why stocks can generate two types of return
- Price appreciation: if the stock's price rises above what you paid, you generate a capital gain if you decide to sell.
- Dividends: some companies periodically distribute part of their profits to shareholders, generating extra income without needing to sell the stock.
Why short-term volatility shouldn't scare you if you invest for the long term
Stock prices fluctuate constantly, sometimes considerably over short periods, reflecting changing expectations, economic news, or geopolitical events. Historically, however, diversified stock markets have tended to recover and grow over long horizons, though this is no guarantee for the future, just a pattern observed in the past.
You don't need to pick individual stocks to take part in the stock market
Unlike the popular image of "picking the winning stock," most individual investors access the stock market in a diversified way through index funds or ETFs, which track the combined performance of hundreds or thousands of companies, without needing to analyze and select individual stocks one by one.
Simulate the effect of investing for the long term
Our compound interest calculator lets you project how a steady investment over time would evolve, under different average annual market return assumptions.