Shares closed at $509.79 (UK£315.31, AUD$482.28) on the NASDAQ index on Friday and had fallen as low as $505.58 (UK£312.71, AUD$478.30) during the day.
That's a considerable drop from the record $705.07 (UK£436.10, AUD$667.02) the company reached on September 19, but still up 26 per cent on the year.
The continued fall follows a lukewarm reception for the iPhone 5 in China, following its launch on Friday, likely due to the expensive premium Apple places on its products.
As a result, two leading industry analysts cut their forecasts for iPhone and iPad shipments during the forthcoming January-March quarter.
Jefferies analyst Peter Misek now expects Apple to ship just (perhaps the most outlandish use of the word 'just' ever) 48 million iPhones during the period. The previous estimate was 52 million.
UBS Investment Research also cut its 12-month stock price target amid the lowered expectations.
UBS analyst Steven Milunovich said: "Some of our Chinese sources do not expect the iPhone 5 to do as well as the iPhone 4S."
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A technology journalist, writer and videographer of many magazines and websites including T3, Gadget Magazine and TechRadar.com. He specializes in applications for smartphones, tablets and handheld devices, with bylines also at The Guardian, WIRED, Trusted Reviews and Wareable. Chris is also the podcast host for The Liverpool Way. As well as tech and football, Chris is a pop-punk fan and enjoys the art of wrasslin'.