Exchange-traded funds tracking real estate, overseas markets and financial institutions all endured volatile trading along with the wider market this week. Real estate-related bundled securities finished higher, after flipping back and forth between the winners and losers column all week. They dropped after American Home Mortgage ( AHM) filed for bankruptcy Monday, rallied Wednesday, the day after the Federal Reserve acknowledged -- but didn't make too big a deal of -- trouble in the credit markets and sank as major homebuilders were swept up in Friday's selloff. Still, ETFs like the Ultra Real Estate ProShares ( URE) finished up $2.34 to $42.75. The iShares Dow Jones US Home Construction ( ITB) gained $2.25 to $27.25. The iShares Dow Jones US Real Estate ( IYR) gained $2.12 to $72. Meanwhile, ETFs tracking banks and financial institutions rallied after the sharp selloffs of the past month. The KBW Bank ( KBE) ETF gained $1.74 to $52. The Regional Bank HOLDRs ( RKH) tacked on $6.32 to $146.04. The iShares Dow Jones US Financial Services ( IYG) added $4.75 to $120.46. The United State Natural Gas ( UNG) ETF soared on rising natural gas prices. Over the course of the week, the front-month natural gas contract gained 73 cents to $6.82 per British thermal unit. The ETF gained $4.50 to $43.50. Bundled securities tracking European markets did not fare as well. On Thursday, French bank BNP Paribas said it has suspended three of its funds with exposure to securities backed by U.S. subprime mortgages, sparking fears that credit woes in the U.S. market were more far-flung than expected. London's FTSE 100 lost 186 points on the week, while Paris' CAC 40 shed 149.26 points. The PowerShares Dynamic Europe ( PEH) lost $1.29 to $23.22. The iShares MSCI France Index ( EWQ) shed 67 cents to $35.51. The iShares MSCI Belgium Index ( EWK) lost 65 cents to $25.25.