Warren Buffett's Berkshire Hathaway lost more than $3.5 billion on Friday as Apple's stock headed for its worst day on Wall Street in more than four years.
Apple — which posted its fifth consecutive week of losses for the first time since 2012 on Friday — finished the day down 6.6 percent, its worst one-day move since January 2014. The Oracle of Omaha owned more than 250 million shares of the Cupertino, California-based company as reported in Berkshire's latest holdings filing at the Securities and Exchange Commission.
At Friday's closing price for Apple of $207.48, Buffett is down $3.7 billion. The company closed at $222.22 on Thursday before the disappointing report.
Apple's stock sank after the company's iPhone shipments for last quarter fell short of analyst expectations. The company also issued a financial outlook for the rest of the year that underwhelmed some investors. Those factors foiled the company's stronger-than-expected earnings and revenue.
However, Buffett's losses are likely even more painful: he told CNBC at the end of August that he bought more Apple shares since the end of June, when he reported that he bumped his stake up by 5 percent.
"We bought just a little [more]," he said about two months ago on CNBC in an interview with Becky Quick.
Earlier this year, Apple became the first publicly traded U.S. company to reach $1 trillion in market value. Berkshire Hathaway is the second-largest holder of Apple shares with a stake worth about $52 billion, according to FactSet.
Despite Wall Street's concerns surrounding the iPhone maker's device sales, Buffett has often explained that his love for Apple stems less from short-term financial performance and more from the power of its brand and ecosystem.
"I do not focus on the sales in the next quarter or the next year," he said in August. "I focus on the ... hundreds, hundreds, hundreds millions of people who practically live their lives by it [iPhone]."
He also called the iPhone "enormously underpriced," saying that it's worth far more than the $1,000 Apple charges for its latest models.
— CNBC's Gina Francolla contributed reporting. Former CNBC correspondent Tae Kim also contributed.