Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you expect the oil and gas industry to thrive as the people on our planet continue to demand lots of energy, the iShares Dow Jones U.S. Oil and Gas Exploration Index ETF
The basics
ETFs often sport lower expense ratios than their mutual fund cousins. The iShares ETF's expense ratio -- its annual fee -- is a relatively low 0.47%. This ETF has performed reasonably well, outperforming the S&P 500
With a low turnover rate of 21%, this fund isn't frantically and frequently rejiggering its holdings, as many funds do.
What's in it?
Several of this ETF's components made strong contributions to its performance over the past year. Chesapeake Energy
Other companies didn't add as much to the ETF's returns last year, but could have an effect in the years to come. Marathon Petroleum
EOG Resources
The big picture
Demand for energy isn't going away anytime soon. 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.