Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you want to invest in the overall economy in a balanced way, the ALPS Equal Sector Weight ETF (NYSE: EQL) could save you a lot of trouble. Instead of trying to figure out which companies will perform best and how to best allocate your money evenly, you can tap this ETF.

The basics
ETFs often sport lower expense ratios than their mutual fund cousins. This ETF's expense ratio -- its annual fee -- is a relatively low 0.54%.

It's too early to draw any conclusions about this ETF's performance, as it's very young, with just a couple years on the books. It has tracked the S&P 500 fairly closely over that time. As with most investments, we can't expect outstanding performances in every quarter or year. Investors with conviction need to wait for their holdings to deliver.

With a low turnover rate of 7%, this fund isn't frantically and frequently rejiggering its holdings, as many funds do.

What's in it?
This ETF's components are actually other ETFs -- namely, nine sector-focused ones. What it does differently than many other ETFs is distribute its assets equally among the nine sectors, thus not ending up over- or under-weighted in any one.

Some of those sector ETFs have made strong contributions to its performance this year. The Utilities Sector SPDR (NYSE: XLU) is up 14% so far this year, as dividend-hungry investors flock to utility stocks. Similarly, the Consumer Staples SPDR (NYSE: XLP) has risen more than 10% in 2011, capitalizing on the defensive tack many investors are taking.

Other sectors didn't add as much to the ETF's returns this year, but could have an effect in the years to come. The Financial Sector SPDR (NYSE: XLF) is down 19% so far in 2011 as banks continue to struggle with problems around the world. Materials Select SPDR (NYSE: XLB) is also down, with a 12% loss this year on fears of a slowdown in China.

The big picture
A well-chosen ETF can grant you instant diversification across any industry or group of companies -- and make investing in and profiting from it that much easier.

Learn about the best dividend ETFs. And if you're looking for some great investments beyond ETFs, consider these 10 Stocks for Your Retirement Portfolio.

Longtime Fool contributor Selena Maranjian doesn't own shares of any company mentioned. Click here to see her holdings and a short bio. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.