Apple’s earnings have just dropped and the investor call is ongoing. Whilst Apple hit the top end of expectations for the current quarter, guidance for the holiday quarter was lower than most investors expected. In an interview with Reuters, Cook blamed three factors for the cautious outlook: differences in iPhone schedule compared to last year, negative impacts from foreign exchange rates, and macroeconomic weakness in ‘select emerging markets’.

With $62.9 billion in revenue for the fiscal Q4 just ended, Apple easily beat consensus revenue estimates of $61.5 billion.

However, it only guided $83-$93 billion in revenue for the forthcoming quarter, fiscal Q1, which is Apple’s seasonal high due to holiday shopping sales. Some investors had predicted guidance approaching $100 billion, and this is the reason for AAPL stock to have fallen by about 4% in aftermarket trading.

It’s interesting that Cook called out weakness in some emerging markets, despite also saying that Apple was pleased with its performance in China. Revenue from China rose 16 percent year-over-year.

We’ll have to wait and see if investors accept Apple’s justifications on the earnings call. Aftermarket trading is more volatile than normal stock trading, and it’s possible that Tim Cook and Luca Maestri on the earnings call will be able to qualm concerns. See our earnings call live blog here.