The Biotech HOLDRs ( BBH) exchange-traded fund was one of Thursday's best performers, rising 2.3%. Genentech ( DNA), which reported better-than-expected earnings after the bell Wednesday, was gaining 4.1%. The ETF was adding $4.34 to $193.57.

Gains of 2% or more in eBay ( EBAY) and Yahoo! ( YHOO) lifted the Internet HOLDRs ( HHH). The ETF was gaining 92 cents, or 1.7%, to $54.73.

The Broadband HOLDRs ( BDH) ETF was also one of the winners. Agere Systems ( AGR) was adding 2.9%, boosting the ETF by 27 cents, or 1.7%, to $15.76.

Oil-related ETFs were also among the losers after crude prices fell below the $52 a barrel level, hitting the lowest level in 19 months. Crude dropped $2.14 to $51.88 a barrel. 

The iPath Goldman Sachs Crude Oil ( OIL) ETF was recently down 2.8% to $32.52. The United States Oil ( USO) ETF was falling 2.5% to $44.15, and the SPDR Oil & Gas Equipment & Services ( XES) ETF was off 1.1% to $26.92. The Oil Services HOLDRs ( OIH) was dipping 0.5% to $126.88.

The iShares Silver Trust ( SLV) ETF was also lower. Silver futures reversed early strength and closed lower by 2 cents at $12.46 an ounce, pressuring the ETF by 0.6% to $122.95.

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