Exchange-traded funds offer a convenient way to invest in sectors or niches that interest you. If you'd like to invest in large-cap companies that appear undervalued, the iShares S&P 500 Value Index ETF (NYSE: IVE) 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 value ETF's expense ratio -- its annual fee -- is a very low 0.18%.

This ETF has slightly underperformed the S&P 500 over the past decade. That's not encouraging, but what matter most is future performance and whether you expect many stock prices to rise from this point on. As with most investments, of course, 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 23%, this fund isn't frantically and frequently rejiggering its holdings, as many funds do.

What's in it?
Plenty of value stocks had strong performances over the past year. For example, Tobacco giant Altria (NYSE: MO) surged 28%, recently hitting a 52-week high. That's impressive, given that its Marlboro cigarettes are losing market share to discount cigarettes, fewer Americans are smoking, and regulations and steep taxes are challenging the company.

Cisco Systems (Nasdaq: CSCO), up 15%, has had a tough time recently as it boosts its efforts in areas such as servers, cuts prices and shrinks its margins, and faces tough competition from Hewlett-Packard, Juniper, and others. On the flip side, it bodes well for Cisco that networking traffic is expected to surge in the coming years.

Other companies didn't do as well last year but could see their fortunes change in years to come. General Electric (NYSE: GE) stayed roughly flat, but it has been busy beefing up its appliance manufacturing, selling off risky finance divisions, expanding into oil operations, and investing in alternative energies.

Ford (NYSE: F), down 27%, has recently reported strong sales, including North American sales levels that were the best in a dozen years. Its management has been doing a great job turning the company around, partly by streamlining its line of car models. Europe's troubles are putting pressure on the company, but eventually things will turn around there, too.

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

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