Midday Leaders and Laggards: Nasdaq 100

The Nasdaq 100 index slipped in midday trading Tuesday as crude-oil prices continued their upward trek and Federal Reserve Chairman Ben Bernanke said a substantial economic downturn seems unlikely, raising speculation interest rates may go up.

The index, which includes 100 of the largest nonfinancial securities listed on the Nasdaq Stock Market, fell 13.51 points to 1,966.20 in midday trading. The broader Nasdaq composite fell 17.77 points to 2,441.69.

Prices for light, sweet crude rose $1.05 to $135.40 a barrel during midday trading on the New York Mercantile Exchange. Last week prices touched a record $139.12.

Shares of personal navigation device maker Garmin Ltd. slipped $2.89, or 5.8 percent, to $46.70.

Shares of graphics chip maker Nvidia Corp. fell for the third day in a row, losing $1.30, or 55 percent, to $22.39.

Shares of computer peripheral maker Logitech International SA shed $1.41, or 4.5 percent, to $30.01.

On the gaining side, shares of Hologic Inc. rose 51 cents, or 2.2 percent, to $23.70. The company, which develops medical diagnostics technology, said late Monday it will buy Third Wave Technologies Inc. for $580 million.

Shares of Amylin Pharmaceuticals Inc. added 59 cents, or 2.2 percent, to $27.43. The company said late Monday once-weekly version of its diabetes drug Byetta lowered blood sugar in patients more than Byetta, which is taken twice daily.

Shares of Apple Inc. gained $3.56, or 2 percent, to $185.17. The company introduced the latest version of its iPhone smart phone Monday.