The recent declines have wiped out nearly $100 billion of Apple's market value - about as much as fellow Dow components Boeing and McDonald's are worth in total. For CEO Tim Cook, it means his stake of 950,000 shares, worth more than $127 million in late April, is now worth around $109 million.
The dropoff represents a notable bout of weakness for a stock basically impervious to pain for the better part of two years.
Strategists pinned the sell-off on the steady run in the shares, as the stock has gained more than 137 percent since hitting a low in April of 2013. In addition, more than 5,700 different funds already own the shares, according to Morningstar data. With Tuesday's declines, the shares have dropped 13 percent over the last 11 trading days.
"When you get a stock that is over-owned it's difficult to find that incremental buyer," said Art Hogan, chief market strategist at Wunderlich Securities in New York.

"It's having its own momentum meltdown," he said.
The declines have left the company's shares below their 200-day moving average, a measure of the long-term trend in the stock. Shares closed at $114.64 on Tuesday.
The last time it closed below the 200-day moving average, in November 2012, the stock was in the midst of a swoon that lasted several more months, finally bottoming out in June 2013.
This week's drop below the moving average exacerbated selling sentiment.
"For a lot of technical traders that was a sell sign," said Channing Smith, managing director at Capital Advisors Inc in Tulsa, Oklahoma. A Capital Advisors growth fund owns shares of Apple but reduced its holdings last year.
"The Apple ecosystem has never been stronger but we are in a very mature cycle. We think Apple will be a good stock, not a great stock going forward," Channing said.
Apple options were busy on Tuesday with about 2.13 million contracts traded, its third-most active day this year, as investors anticipate more volatility in the stock.