NEW YORK ( TheStreet) -- The past few weeks of tumultuous action have weighed heavily on investors of all risk tolerances. Although euro-concerns and other macroeconomic issues will likely continue to keep many from attempting to reenter the global marketplace, there remain individuals who may be ready to bet on strength.If the developed market can get itself back on the healing path, and emerging countries can return to strength, growth-correlated industries such as coal, steel, and timber could be attractive destinations for aggressive investors. Using ETFs, it is possible to gain concentrated exposure to these market slices. Infrastructure has become a major focus of the Obama administration as evidenced by the president's proposed plan to create a national infrastructure bank. As developed nations turn their attention to their aging bridges and roads and emerging nations work to further develop their own public works projects, steel will be sure to be a major ingredient. Investors can target the companies responsible for the production of this alloy using the Market Vectors Steel ETF ( SLX). SLX's index is unique in that it spreads its assets across both steel producers and iron-ore miners. By placing firms like Posco ( PKX) and ArcelorMittal ( MT) alongside Vale and Rio Tinto ( RIO), the fund is well suited to handle a wide variety of industry-related scenarios. As I explained in this week's video (insert video link), coal will be a commodity to keep an eye on in the event that the global markets can shake off this current bout of jitters. In recent years, we have watched as nations like China and Brazil have evolved into leading economic growth engines. Powering their respective expansions will require massive amounts of energy. Coal will likely represent a major slice of this energy demand. The Market Vectors Coal ETF ( KOL) targets a diversified collection of domestic and international coal producers, equipment providers, and power generators. Companies comprising the fund's top positions include China Shinhua Energy, Consol Energy ( CNX), Peabody Energy ( BTU) and Bumi Resources. Timber may be worth keeping an eye on in the event that the global marketplace turns higher as well. As we learned from Tuesday's sub-par housing starts report, the residential real estate market continues to face substantial headwinds. This will likely continue to weigh on the broad timber and forestry industry.