In his latest note to investors issued Tuesday afternoon, analyst Gene Munster of Piper Jaffray said Apple typically outperforms in the last four months of the year, up 43 percent, and underperforms in the first four months of the year, up 2 percent. This year, he said, investors are just taking their typical sell-off a little early, to capitalize on the strong gains of late '09.
In addition, he said shares may have, in years past, been driven up in December in anticipation of Apple's participation in the Macworld conference. The company's 2009 appearance was its last.
Munster said he remains confident that the December quarter will provide upside, driven by Mac, to reassure investors.
"There has been disagreement on the Street as to what has caused the recent slide in AAPL shares," he said. "We believe it is the cumulative effect of several seasonal and industry wide market forces at work."
Another factor in Apple's recent stock struggles: The ongoing ad war between Verizon and AT&T, and the recent launch of the Motorola Droid, also accompanied by an advertising blitz.
"Collectively, these competitive forces may have had a slight negative impact on consumer sentiment towards the iPhone," Munster said. "Also, large cap stocks GOOG, AMZN, QCOM and AAPL have each underperformed the market in the past 5 trading days."