Exchange-traded funds tracking energy were among the decliners this week despite an extraordinarily strong week for crude-oil futures.

Crude prices gathered an enormous amount of upward momentum this week and, in quick succession, smashed past the $130 and the $135 marks before easing to a 4.6% surge at $132.19 a barrel. Amid those moves, however, oil-and-gas giants Exxon Mobil ( XOM) and ConocoPhillips ( COP) each lost ground for the week as investors ended the week with profit-taking.

The Oil Service HOLDRs ( OIH) ETF was off 3.2% for the week, Energy Select Sector SPDR ( XLE) sank 3%, and iShares Dow Jones U.S. Energy Sector ( IYE) gave up 2%.

At the same time, concerns over rising fuel prices stuck it to transportation stocks, and the iShares Dow Jones Transportation Average ( IYT) surrendered 4.2% over the past five sessions.

The SPDR S&P Homebuilders ( XHB) fund, meanwhile, plummeted 12.1% over the past week. Friday saw miserable existing-home sales data come to light, with the National Association of Realtors saying the housing backlog is at a 23-year high. Also, on Thursday, the Office of Federal Housing Administration said home prices suffered their worst quarterly drop on record last quarter, according to its purchase-only house-price index.

Financial-space ETFs were also particularly hard hit in a week that saw Oppenheimer analyst Meredith Whitney predict that banks will take writedowns of at least another $170 billion by the end of next year, and that the effects of the credit crisis could linger even past 2009. Also earlier this week, The Wall Street Journal said that some banks' hedging strategies -- betting against funds tracking real estate and leveraged loans, for instance -- have backfired amid recovering U.S. shares this quarter.

The paper cited Lehman Brothers ( LEH) and Morgan Stanley ( MS) as among those hurt by that tactic. Shares of the firms plunged 17.3% and 11.4%, respectively.

The Financial Select Sector SPDR ( XLF) lost 6.7% since Monday; Ultra Financials ProShares ( UYG) tumbled 10.9%; Vanguard Financials ETF ( VFH) shed 5.3%; and iShares Dow Jones U.S. Financial ( IYF) was off 5.5%.

Among suffering individual names, Dow financial components Citigroup ( C), Bank of America ( BAC), and JPMorgan Chase ( JPM), slid at least 6.2% apiece.

On the lonely upside were gold-related ETFs, which gained ground for the week as futures on the metal glided higher by nearly 3% on a weakening U.S. dollar. The iShares COMEX Gold Trust ( IAU) and the SPDR Gold Trust ( GLD) have risen 2.4% over the past five sessions, and Market Vectors Gold Miners ETF ( GDX) is better by 0.9%.

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