Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you expect undervalued large companies to perform well over time, as they eventually approach their intrinsic value, the PowerShares Fundamental Pure Large Value Portfolio ETF (NYSE: PXLV) could save you a lot of trouble. Instead of trying to figure out which companies will perform best, you can use this ETF to invest in lots of them simultaneously.

The basics
ETFs often sport lower expense ratios than their mutual fund cousins. The PowerShares ETF's expense ratio -- its annual fee -- is a relatively low 0.39%.

This ETF doesn't have much of a performance record yet, as it's still less than a year old. It's very small, too, so if you're thinking of buying, beware of occasionally large spreads between its bid and ask prices. You might want to just keep an eye on it as it matures a bit, or you might want to be an early investor. Remember that 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.

What's in it?
As with any diversified ETF, some stocks in its portfolio went up strongly. Tobacco giant Altria (NYSE: MO) gained 27% over the past year, generating billions of dollars in profits despite domestic headwinds such as rising taxes and regulations, leading to a shrinking base of smokers.

Duke Energy (NYSE: DUK) also gained 27%, despite facing lower demand due to mild weather, as well as significant emission charges and steep construction costs as it expands its capacity. On the bright side, international growth has been strong. Meanwhile, US Bancorp (NYSE: USB) advanced 9%, showing stronger financial health than many of its peers, along with robust growth. One sign of management confidence is that after slashing its dividend between 2008 and 2009, the payout was boosted by 150% last year.

Other companies didn't do as well last year but have promise to rebound this year and beyond. Ford (NYSE: F) fell 36%, partly on rising commodity prices and a surprising earnings disappointment. But there's much to be hopeful about, as the company boldly redesigns its popular Fusion and aggressively expands abroad.

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 5 ETFs That Could Soar in 2012. And if you're looking for some great investments beyond ETFs, consider these 12 Dividend Stocks for 2012.

Longtime Fool contributor Selena Maranjian owns shares of Ford Motor, but she holds no other position in any company mentioned. Click here to see her holdings and a short bio. The Motley Fool owns shares of Altria and Ford. Motley Fool newsletter services have recommended buying shares of and creating a synthetic long position in Ford. 

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