Apple's shares are in decline. The stock has fallen more than 16 per cent since closing at a 52-week high of $85.59 on January 13.

On Monday night it fell $4.55 from just over $72, closing at $67.30. This is still much higher than Apple 52-week low of $33.11.

American Technology Research Shaw Wu told Reuters: "The stock has been under some selling pressure for the past week."

Wu suggested that some investors are concerned about Apple's transition to Intel chips. A view backed by Apple chief financial officer Peter Oppenheimer, who admitted in January that his companies shift to Intel chips had already caused a drop in sales.

Apple shares took a hit after January 18, when the company forecast current-quarter results below analysts' estimates.