Shorting stocks which are index components can be very tricky, because if the index (Nasdaq 100, SOX) is moving up, it will have a tendency to drag up the components. When you short a stock like AMAT, you are in effect making a short bet on the overall index (SOX, Nasdaq100) also. If you don't believe the overall index will fall further, then you should rethink your short entry. For example, right now I don't think is a good risk-reward entry for putting a big short on SOX index.
The SOX is still the "Goto" index for hot money chasing high-beta "growth" stocks. When/If there is a knee-jerk war rally, you can be sure everybody (funds, traders, shorts) will be trying to buy/cover all the SOX they can get.