This Week's ETF Winners & Losers

Exchange-traded funds tracking the financial sector were some of the worst performers of the week as the space was hit with a deluge of rotten news.

The Financial Select Sector SPDR (XLF Quote) slid 6.1%, and the iShares Dow Jones U.S. Broker-Dealers (IAI Quote) ETF lost 5.6%. The iShares Dow Jones U.S. Financial Services (IYG Quote) was off 6.5%.

The moves came as financials were battered with one bad piece of news after another, especially in the latter half of the week. Most recently, margin calls at Thornburg Mortgage (TMA Quote), as well as word that Swiss bank UBS (UBS Quote) had cheaply sold a large chunk of mortgage securities, dragged down shares at those names and worked to throttle the rest of the market.

Before that, closely watched bond insurer Ambac (ABK Quote) deflated Wall Street after announced a thinner-than-anticipated capital-boosting plan.

Bundled securities tracking retail shares likewise slid for the week even though the world's biggest retailer, Wal-Mart (WMT Quote), came out with better-than-expected same-store sales numbers along with rival Target (TGT Quote).

Amid another pile of evidence pointing to a declining economy, however, taking losses this week were the Retail HOLDRs (RTH Quote) and the SPDR S&P Retail (XRT Quote) ETF, which surrendered 1.9% and 5%, respectively.

Among few ETFs on the rise were those tracking energy and oil. Shares rallied as crude prices hit all-time highs nearly every day this week, the dollar weakened to a string of record lows, and OPEC decided not to increase its production targets. Crude oil finished the week up $3.31 to $105.15 a barrel.

For the week, the iPath S&P GSCI Crude Oil Index (OIL Quote) added 3.9%. The United States Oil (USO Quote) ETF climbed 4.1%, and the PowerShares DB Oil (DBO Quote) tacked on 3.9%.