They can make money on volatility, up or down. My uneducated guess is that they use the quarter figures as an indicator to make it easier to push the price down

They can make money on volatility, up or down. My uneducated guess is that they use the quarter figures as an indicator to make it easier to push the price down. I don't think there is any long term reason for the stock to go down based on the latest quarter. Google are putting more ads in front of people, which means those bidding lower are getting more clicks, that will be why the average cost per click is down. Google is making big changes in shopping and ecommerce ads which they stand to make a lot from long term.