Apple reported its Q3 2011 numbers this week, for the July to September period. The iPad volumes were in-line with expectations, but its iPhone shipments were disappointing. Global iPhone shipments reached 17.1 million units in Q3 2011, growing only 21% from a year earlier. This compares with a huge 126% annual growth rate during the first half of 2011. Those contrasting ratios illustrate just how much Apple slowed down.

What caused the slowdown? 

First, we think many consumers and operators held off buying the iPhone 4 during September in anticipation of a new iPhone 4S in October. Second, waning economic confidence has capped demand for premium goods in some regions. And third, the Samsung Galaxy S2 superphone is on a roll and providing tougher competition.

Apple's guidance for Q4 2011 is that it will be a record iPhone and iPad quarter. Our forecasts agree. The iPhone 4 and iPad 2 are new products that will be heavily subsidized and wildly popular during the western holiday season.

So, Q3 was a temporary blip, and Q4 will see Apple roar back... But let's not forget that this is the second stumble under Apple's new management. We believe the iPhone 4S was a delayed launch and now Q3 iPhone shipments have underwhelmed. And if the Amazon Fire starts to chip away at the iPad 2 in November, Apple Inc. could quickly find itself in trouble.

- Scott Bicheno