It could be something like short pullback after reaching new high several days ago. The market is growing for several months, so it may need the short correction to "take a rest". Of course, summer is relatively low season for business activity, so we could see possible decrease of volatiliy and volumes. At the same time, the summer earnings season could be quite interesting (the previous one was almost perfect). Another point is that the reaction to the unexpected news could be sufficient due to the relatively low general trading volumes and dozens of traders looking for trading opportunities.