This Week's ETF Winners & Losers

Exchange-traded funds tracking oil were some of the worst performers this week as a surging U.S. dollar sharply pulled down oil prices following a days-long tear into record territory.

Oil started the week off with a bang after news broke that Nigerian militants had attacked two oil pipelines, but the crude rally cooled after the greenback staged a big recovery Thursday. Futures took back a great deal of those losses Friday as fresh supply worries cropped up, but oil-related stocks ended up beaten down for the week.

Oil Services HOLDRs (OIH Quote) slid 3% for the week, the PowerShares Dynamic Oil & Gas Services (PXJ Quote) fund was down 1.7%, and the iShares Dow Jones U.S. Energy (IYE Quote) declined 0.8%.

Bundled securities tracking gold-related shares also fell over the past five sessions as the metal followed oil downward Thursday amid a stronger dollar.

Since Monday, the Market Vectors Gold Miners ETF (GDX Quote) has tumbled 9%, the iShares COMEX Gold Trust (IAU Quote) has dropped 4%, and streetTRACKS Gold Shares (GLD Quote) has given up 3.7%.

On the flip side, ETFs tracking the financial sector clambered upward as investors continued to find clues that the group has weathered the credit storm and is poised for recovery. Merrill Lynch (MER Quote), for instance, maintained its dividend, indicating that it now has a healthy cash pile and can thus afford to do so. The stock added 4.8% for the week.

The week also saw National City (NCC Quote) slashing its dividend, posting a quarterly loss, and launching a heavily discounted equity sale in an effort to raise capital, and Ambac (ABK Quote) swung to a big shortfall as well. Nat City plummeted 24.1% over the past five sessions, and Ambac tanked 35.5%. Still, the sector was generally in better shape at the end of the week.

The Financial Select Sector SPDR (XLF Quote) and the iShares Dow Jones U.S. Financial Sector (IYF Quote) ETF each tacked on 1.9% for the week, and the Ultra Financials ProShares (UYG Quote) climbed 3.6%.