Investing 101: Stocks, Bonds, Mutual Funds, and ETFs

You know why investing works (Part 1) and you know which account to open (Part 2). Now we open the container and decide what goes inside.

There are only a handful of building blocks worth understanding when you start, and two of them you have already met. Let me walk through each, then show you the tool that lets you own a thousand of them at once without becoming an expert in any.

Stocks: Owning a Piece

A stock is a share of a company. Buy one share of a business and you own a tiny part of it, which means you benefit when the company grows and you feel it when the company struggles.

Stocks have done the most for investors over long stretches of history, which is the reward for putting up with their swings. They can rise sharply and fall just as sharply. A single company can also fail outright, and shareholders often lose everything when that happens. So stocks are where the growth comes from, and also where the white knuckles come from.

Bonds: Lending Instead of Owning

A bond is a loan you make. You hand money to a company or a government, they agree to pay you interest along the way, and they promise to give your money back on a set date.

Because a bond is a contract with scheduled payments, it tends to be steadier than a stock. The trade-off is that it usually earns less over the long run. Bonds are the ballast in a boat. They will not win you the race, but they keep the whole thing from tipping over when the water gets rough. As you get closer to needing your money, bonds matter more.

Mutual Funds: The Basket

Here is where investing gets a lot easier for a regular person. Picking individual stocks well is genuinely hard, even for professionals who do it full time, and getting it wrong with one or two companies can sting. A mutual fund solves that.

A mutual fund pools money from many people and buys a large basket of investments with it. Buy one share of the fund and you instantly own a slice of everything in the basket, sometimes hundreds or thousands of companies. If one of them stumbles, it is a small piece of what you hold, not the whole thing.

Some mutual funds are run by a manager who tries to beat the market by choosing what to buy and sell. These are called active funds, and they tend to charge more. Others, called index funds, simply own everything in a particular market and aim to match it rather than beat it. They are cheaper to run, so they cost you less.

ETFs: The Basket That Trades Like a Stock

An ETF, or exchange-traded fund, is close cousin to a mutual fund. It is the same idea, a basket of many investments in one purchase. The main difference is that an ETF trades on the market throughout the day the way a single stock does, and many of the most popular ETFs are low-cost index funds. For most beginners, a broad index ETF and a broad index mutual fund do nearly the same job.

Why Cost Quietly Decides So Much

Funds charge a yearly fee called an expense ratio, written as a percentage of what you have invested. The differences look tiny and turn out to be enormous. A broad index fund might charge three hundredths of one percent, while a pricier fund might charge a full percent or more. That gap may sound trivial. Stretched over 30 or 40 years of compounding, it can quietly hand away a large slice of everything you earned.

This is one of the few things in investing you control completely. You cannot control what the market does next year. You can control what you pay to participate in it.

What to Do With All This

For someone starting out, broad, low-cost index funds are the sensible foundation. A handful of them can give you ownership in the whole U.S. market, companies overseas, and bonds for stability, all for very little. That foundation is not the end of the story. There are also well-built funds that tilt toward characteristics that have rewarded patient investors over long periods, and a small number of skilled active managers who earn their keep in corners of the market where indexing is weaker. The work, and the value, is in telling the genuinely good, low-cost funds apart from the well-marketed ones. That is research, not guesswork, and it is where careful homework pays off.

If you want the deeper version of any of this, two companion pieces go further than we can here: Understanding the Stock Market and Understanding the Bond Market.

Before You Move On

The vocabulary is the hard part. The ideas are not:

• A stock is ownership; a bond is a loan you make.
• A mutual fund or ETF is a basket that lets you own many investments in one purchase.
• Index funds aim to match a market cheaply; active funds try to beat it and cost more.
• Over decades, the fee you pay matters more than almost anything else you can control.

In Part 4 we take these building blocks and put them together into a single, sensible portfolio, and I will show you why spreading your money out is the closest thing investing has to a free lunch.