NEW YORK ( TheStreet) -- The developed world's debt issues have commanded headlines and weighed heavily on investor sentiment in recent weeks.As Washington lawmakers and world leaders continue to seek the best way to solve their respective issues, it may be tempting for some investors to head for the exits. This, however, should not a prime course of action. On the contrary, as we have seen throughout the current earning season, many domestic companies continue to exhibit strength despite the ongoing threat of economic turbulence. Instead of fleeing for the exits, long-term investors should consider doing some portfolio maintenance. By constructing a well-rounded portfolio it is possible to weather the effects of negative headlines and prepare for when the global markets revert back to the healing path. One attractive destination for wearied, though eager investors are mega-cap stocks. Earlier this year I made the case for these industry behemoths. Though often panned for being slow moving and boring, the size, liquidity, and global reach of firms like General Electric ( GE), Exxon Mobil ( XOM) and Microsoft ( MSFT) will ensure long-term, stable performance. This can be an endearing quality, especially during periods of sweeping duress and turmoil. The iShares S&P 100 Index Fund ( OEF) is one of the largest and most reliable ETF options for investors looking to target the leaders of the business world. Designed to home in on the largest publicly traded companies based in the U.S., top holdings include Exxon, Apple ( AAPL), International Business Machines ( IBM), Chevron ( CVX) and Microsoft. A well-balanced option, OEF sets aside less than one-third of its assets to the top 10 index components. I was early in calling for investors to turn to mega-cap ETFs like OEF at the start of the year. Despite bloody political protests sweeping through the Middle East and Northern Africa, and the natural disasters that struck Japan, investors proved resilient and unwilling to shy away from riskier small and mid-cap stocks. Mid-caps, in particular, have proven to be particularly attractive in 2011. On a year-to-date basis, ETFs like the SPDR S&P Midcap 400 ETF ( MDY) and Rydex S&P 400 Pure Growth ETF ( RFG) have managed to outpace funds focused on other segments of the style box.