The Motley Fool has helped ordinary people become better investors for nearly two decades. This month, we're reaching out to millions of investors to help guide them in their quest toward financial knowledge and independence.

Along those lines, I'm planning to take a look at many of the most popular exchange-traded funds in the market today. ETFs have skyrocketed in popularity, but it's important to understand exactly what you're getting when you buy an ETF. Today, I'd like to focus on the SPDR Dow Jones Industrial Average ETF (NYSE: DIA), also known colloquially as the Dow Diamonds.

Candlestick chart laid over line graph

Image source: Getty Images.

Why buy Dow Diamonds?
The Dow Diamonds ETF is an old-timer in the ETF world, having started trading at the beginning of 1998. Its purpose is simple: It tracks the Dow Jones Industrial Average (INDEX: ^DJI), the premier blue-chip index of U.S. stocks. Although there's no hard-and-fast rule, each share of the Dow Diamonds corresponds to about 1% of the current value of the Dow.

Inside the ETF, you'll find shares of all 30 Dow stocks, all with the exact same number of shares of stock. That's because unlike many benchmarks, the Dow is price-weighted. Price weighting presents challenges in some cases, but it has the benefit of making ETF-tracking easy. Investors have plowed about $21 billion into the ETF.

One nice benefit of owning Dow Diamonds is that the ETF pays a healthy dividend yield. Right now, the ETF's yield is about 2.4%, thanks in large part to outsized contributions from some of the heftier dividend-payers in the Dow. For instance, Dow telecom stocks AT&T (NYSE: T) and Verizon (NYSE: VZ) have to spend a lot of money on improving their networks, but between landlines and other monthly customer income, the businesses are cash cows. High levels of cash flow support dividends in the 4% to 5% range, even as the two stocks have risen to multiyear highs recently. All in all, at current prices, you can expect to get about $240 in dividends every year for every $10,000 you invest in the Dow Diamonds.

The Dow Diamonds are also relatively inexpensive to own. Annual expenses of $18 for every $10,000 you invest aren't the absolute lowest in the business, but they're fairly attractive compared to the overall universe of ETFs.

Learn more
If you like the Dow, the Dow Diamonds ETF gives you an easy way to own all 30 Dow stocks in a single investment. To learn more about the Dow Diamonds, use this link to the ETF's main information page, and be sure to follow the Fool's daily coverage on the Dow using our My Watchlist feature.

Let me also encourage you to take a look at the special website we've set up at InvestBetterDay.com. On Sept. 25, we're taking a day to celebrate the art of investing, and we encourage your participation. Take a look at the site now and get on the path to personal prosperity.