The Utilities HOLDRs ( UTH) was the session's best performer Monday as TXU ( TXU) said it will go private through the largest leveraged buyout in history. The ETF was higher by $4.10, or 3%, to $139.71.

Other utility-related ETFs were also faring well. The Utilities Select Sector SPDR ( XLU) ETF was tacking on 2.5% to $39.63. The iShares Dow Jones US Utilities ( IDU) ETF was higher by 2.2% to $96.40.

The PowerShares Lux Nanotech ( PXN) ETF was also gaining ground after holdings Altair Nanotechnologies ( ALTI) and Cambridge Display Technology ( OLED) were up by 4.6% and 4.1%, respectively. The ETF was higher by 20 cents, or 1.1%, to $17.94.

On the other hand, transportation stocks were weaker as the price of oil pushed as high as $61.75 a barrel. The iShares Dow Jones Transportation Average ( IYT) ETF was losing $2.10, or 2.3%, to $90.49.

The B2B Internet HOLDRs ( BHH) was one of the session's worst performers as holding CheckFree ( CKFR) was falling nearly 1.5%. The ETF was down 3 cents, or 1.6%, to $2.24.