The PowerShares Lux Nanotech ( PXN) exchange-traded fund was the top performer of Monday's winning session, thanks to large gains in several of its holdings.

Among them, Altair Nanotechnologies ( ALTI), Nanophase Technologies ( NANX) and Elan ( ELN) were all up more than 3%.

The PowerShares Lux Nanotech ETF was recently higher by 83 cents, or 4.8%, to $18.16.

An earnings beat by Merck ( MRK) boosted several pharmaceutical ETFs. The Pharmaceutical HOLDRs ( PPH) was gaining $1.78, or 2.2%, to $82.55. The SPDR S&P Pharmaceuticals ( XPH) rose 57 cents, or 1.6%, to $35.88. The iShares Dow Jones U.S. Pharmaceuticals ( IHE) was up 86 cents, or 1.5%, to $56.62.

Bundled securities tracking Chinese markets were also among the winners to start the week. Overnight, China's CSI 300 Index jumped nearly 5%. The iShares FTSE/Xinhua China 25 Index ( FXI) ETF climbed $4.37, or 3.2%, to $142.61. The SPDR S&P China ( GXC) was adding $2.36, or 3.2%, to $75.15. The SPDR S&P Emerging Asia Pacific ( GMF) was tacking on $2.09, or 2.7%, to $80.08.

On the flip side, the United States Natural Gas ( UNG) ETF was the biggest loser, as natural gas futures fell by 35 cents to $6.09 per million British thermal units. The ETF was falling by $2.09, or 5.1%, to $39.01.

Oil-related ETFs were also losing ground, as the new front-month September crude contract shed 89 cent to $74.90 a barrel. The iShares Dow Jones U.S. Oil & Gas Exploration Index ( IEO) was down 96 cents, or 1.6%, to $59.42. The SPDR S&P Oil & Gas Exploration & Production ( XOP) was lower by 71 cents, or 1.5%, to $47.09. The United States Oil ( USO) ETF was off 76 cents, or 1.3%, to $56.24.

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