Many corporate bond ETFs, including the ultra-popular LQD, tend to have significant biases towards financial stocks. For those looking to diversify a bit, the iShares Utilities Sector Bond (AMPS) can be a useful way to tilt towards slightly lower risk securities. Another interesting fund is the Industrials Sector Bond Fund (ENGN), which focuses on companies in a number of sectors, including health care, consumer staples, and consumer discretionaries. For investors looking to fine-tune their fixed income allocations, ETFs such as ENGN and AMPS can be quite handy.

Bottom Line: Consider using sector-specific bond ETFs to round out your portfolio's fixed income component.

100. China A-Shares Round Out Exposure

There are more than a dozen ETFs that offer exposure to Chinese stocks now available to U.S. investors, presenting a number of choices for those looking to tap in to the world's most important economy. But only one of those focuses on China's A-Shares market, securities that trade on exchanges in Shanghai and Shenzen and are denominated in the local Chinese currency. Access to the A-Shares market has historically been limited by the Chinese government, but in recent years it has opened up to foreigners.

The A-Shares market can represent a way for investors to round out their China exposure; though some stocks are traded on multiple exchanges, a number of companies are only available as A-Shares. The A-Shares market is also more likely to include smaller companies that derive most of their revenues domestically, potentially making them better tools to capture the growth in China's economy.

PEK is potentially a unique and very useful tool, but there are some caveats. The underlying holdings are swap contracts, and the ETF usually trades at a meaningful premium to NAV (though the premium fluctuates quite a bit).

Bottom Line: Investing in the China A-Shares market can offer more of a "pure play" on the local economy.

101. Free ETF Tools And Resources

For investors interested in harnessing the tremendous potential of ETFs-whether for a long-term, buy-and-hold portfolio, or through more active tactical management-there are a number of free tools and resources out there that can be used to filter the 1,400+ ETPs and evaluate the merits of potential investment. Some of the tools on ETFdb.com include:

ETF Screener: Filter the universe of ETPs by dozens of descriptive criteria; ETFdb Pro members can download complete results into Excel or CSV files.