Apple is the worst-performing stock in the S&P 500 so far this year, Howard Silverblatt, senior index analyst at S&P Dow Jones Indices, told The Huffington Post on Monday.
The company's stock price has plunged 16.9 percent in 2013, according to Google Finance. In contrast, the S&P 500 as a whole has risen 2.7 percent since the beginning of January.
Apple's share price was $442.32 at the end of trading on Monday.
Evidence that Apple may be losing its dominance in the smartphone market drove its share price down in late January, causing the company to lose its title of the world's most valuable company to Exxon Mobil.
Samsung Galaxy smartphones have been outselling Apple iPhones for a year now, according to the Associated Press.
Apple's underwhelming sales figures have spurred analysts to cut projections of the company's future stock price, according to Reuters.
In an effort to appease its shareholders last year, Apple issued a dividend for the first time in nearly two decades. But there are lingering concerns that Apple CEO Tim Cook won't be able to replicate his predecessor Steve Jobs' success.