coinmaker77 already knows what is happening. If you liked this thread, you will love the next 10 or 20 times he will post the same message.
April is when Intel employees are reviewed and stock options are awarded. April is also the anniversary month when previous years options vest. The RSU options are awarded with a strike price of $0. When the options vest, Intel collects estimated taxes and moves the cost basis to the market price. Intel usually has to sell about 1/3 of the shares for estimated taxes. For every insider vesting option, you will see the award logged as an "option exercise" and then followed the next day by the SELL of the 1/3 tax shares.
There are a couple of Intel insider sellers but nothing like you find on the QCOM or ARMH list.