Volume picked up considerably yesterday in iShares PHLX SOX Semiconductor (NasdaqGM: SOXX), with more than 700,000 shares changing hands in the ETF (versus average daily trading volume of 234,000 shares).

It is not unusual for us to see accelerated activity in Semi related products as we are entering corporate earnings season, and Semi name AMD announced that quarterly sales fell 11% and that they were reducing forecasts for the current quarter yesterday.

While not a top holding in SOXX specifically, the AMD news still puts into perspective the coming earnings season and the need or want of portfolio managers to effectively get exposure, or hedge exposure to the influential Semi sector.

Current SOXX top weightings are INTC (8.91%), TSM (8.55%), BRCM (8.07%), TXN (7.91%), and AMAT (7.61%).

BlackRock’s iShares recently noted to us that short interest levels in SOXX as well as in related ETF, Market Vectors Semiconductor (NYSEArca: SMH).

SMH tracks the Market Vectors U.S. Listed Semiconductor 25 Index, with heavy weightings to INTC and TSM (which make up 20.98% and 13.35% respectively of the ETF).