The First Trust ISE Global Engineering and Construction Index (">NYSEARCA:FLM) has gained 5% since being listed in October 2008. The S&P Supercomposite Construction and Engineering Index (">S15CSTEX:IND) also has performed well, showing an initial investment of $10,000 in 2006 to be worth $22,094 today, Invesco says.

Ups and Downs
Individual companies have been hammered this year. For example, last summer, Atlas Copco saw its stock trading at 175.60 Swedish kroner; in 2012, the price fell sharply to 112.30 kroner, and by Aug. 9, it rebounded to 158.50 kroner. The Shaw Group (">NYSE:SHAW), with a record $42-billion backlog, has seen wild stock price swings: a $43.70 high and a $18.98 low over just the past year. The Shaw Group is now being acquired by CB&I (">NYSE:CBI).

Graves says ETFs are geared for long-term appreciation, and the holdings in the fund itself are not heavily traded. This strategy can buffer volatility. "There are periodic rebalancing maneuvers, but an ETF takes a net-long position," he tells ENR. That means, generally, that ETF managers are not going to be short-selling holdings.

An ETF strategy isn't immune to volatility in the construction sector, though. PXR is down more than $7 per share over the past 12 months but up more than $17 per share since the fund's initial listing in 2006. Mastec was trading on Aug. 9 at $18.24; over the past year, it has seen a high of $22.72 and a low of $12.86 per share. GRID can be bought today for $27.76; over the past year, it has traded as high as $28.92 and as low as $22.16 per share.

"Emerging markets are going to be more volatile because, often, there aren't the established business models and companies at work like in the developed world," says Taylor Ames, equity research analyst for Invesco. "The fundamentals are strong, but these markets still move on news in the developed world—will Greece leave the EU? How is Spain recovering?"