Stocks, Funds and ETFs: A Beginner’s Glossary

Investing jargon can make the basics sound more complicated than they are. Most beginner investors only need to understand a handful of terms to make sensible decisions: what a stock is, what a fund is, the difference between mutual funds, index funds and ETFs, and what drives returns and costs. This guide defines each term in plain language, then shows how they fit together.

Stock

A stock, or share, is a small piece of ownership in a company. If the company grows and becomes more profitable, its shares tend to become more valuable, and some companies pay part of their profits to shareholders as dividends. If the company struggles, the share price can fall, sometimes to zero. Individual stocks can swing sharply in price based on company news, the economy and investor sentiment.

Bond

A bond is a loan to a government or company, which pays interest and returns the original amount at a set date. Bonds are generally less volatile than stocks and tend to grow more slowly. Many investors hold both, increasing the share of bonds as they near the time they need the money.

Mutual fund

A mutual fund pools money from many investors and buys a collection of stocks, bonds or other assets. Instead of buying dozens or hundreds of companies yourself, you buy shares of the fund. Mutual funds are priced once a day, after the market closes. Many are actively managed, meaning professional managers choose investments trying to beat the market.

Index fund

An index fund is a fund that simply tracks a market index, such as the S&P 500, which follows about 500 large US companies, or a total market index that includes thousands. Because no one is picking stocks, index funds usually have very low costs. Long-running research, including S&P Dow Jones Indices' regular SPIVA reports, has found that most actively managed funds fail to beat their benchmark index over long periods, after fees. That is one reason index funds have become popular with long-term investors.

ETF

An exchange-traded fund is a fund that trades on a stock exchange like an individual stock, so its price changes throughout the day. Many ETFs track indexes and have low costs. In practice, an index mutual fund and an index ETF tracking the same index can be very similar investments. ETFs are often more tax-efficient in taxable accounts and have no minimum investment beyond the price of one share, or even a fraction of a share at many brokers.

Expense ratio

The expense ratio is the annual fee a fund charges, expressed as a percentage of your investment. A fund with a 0.05 percent expense ratio costs $5 a year for every $10,000 invested, while one with a 1 percent ratio costs $100. Over decades, that difference compounds into a significant amount, so costs are one of the few things investors can control.

Diversification

Diversification means spreading money across many investments so that a problem with one company or sector does not sink your portfolio. Buying a broad index fund is a simple way to diversify instantly. Owning shares in your employer, or concentrating in a single exciting sector, increases risk.

Return and volatility

Over long periods, US stocks have historically returned around 10 percent a year on average before inflation, based on the S&P 500's long-run record, but with large swings along the way. The index has fallen more than 30 percent in some years, such as during the 2008 financial crisis and briefly in 2020. Past returns don't guarantee future results. For this reason, money you will need within the next few years is usually kept in safer places, such as savings accounts or short-term bonds.

Capital gains

When you sell an investment for more than you paid, the profit is a capital gain. In the US, gains on investments held for more than a year are generally taxed at lower long-term rates than those held for a year or less. Investments inside retirement accounts such as 401(k)s and IRAs grow without annual taxes on gains, which is a major advantage.

How it fits together

For many beginners, a simple approach is to invest regularly in one or a few low-cost, broadly diversified index funds or ETFs, inside a tax-advantaged account if possible, and to choose a mix of stocks and bonds that matches how long the money will be invested and how much short-term fluctuation you can tolerate. Target-date funds do this automatically by gradually becoming more conservative as a chosen year approaches.

Getting started

• Through work: a 401(k) or similar plan, especially with an employer match, is often the first place to invest. Plans offer a menu of funds, often including index and target-date funds.
• On your own: open an IRA or a regular brokerage account with a low-cost broker. Many have no account minimums and allow fractional shares.
• Automate: set up regular contributions, which spreads purchases over time, an approach known as dollar-cost averaging.

Common beginner mistakes

• Selling in a panic during market drops, which locks in losses.
• Chasing last year's best-performing fund or stock.
• Ignoring fees.
• Trading frequently based on news or social media tips.
• Investing money needed for short-term goals or an emergency.

Investing involves risk, and this is general information rather than personal advice. A fee-only financial planner can help if your situation is complicated.