3Q earnings expected to show large improvement.
Market buoyed by Apple's best 4-day run since 2014.
Apple surges; technology companies gain ground.
Chemical maker will pay $57 billion for American seed maker.
Technology companies trade higher
Investors worry that the global economy is growing at a slower clip.
Federal Reserve member said the central bank should be careful about raising rates.
Federal Reserve slated to decide later this month.
Apple slumps almost 3% day after iPhone release
But Nasdaq does eke out record-high close.