Spare a thought for Warren Buffett, whose portfolio is not doing him any favors this week.
On Monday, Buffett lost nearly $1 billion on his third-largest investment, IBM, after the company posted disappointing earnings.
Read MoreBuffett sells 'huge mistake'
Coke is Buffett's second-largest investment and has been one of the stalwarts of his portfolio for decades. (He left Coke's board in 2006 and his son Howard took a board seat there in 2010.)
With 400 million shares, Tuesday's decline of $2.72 cost the Oracle of Omaha $1.09 billion. Shares were on track for their worst day since October 2008. (With IBM's $7 decline on Tuesday, he was out another $494 million there, too).
"I love Coke. I love the management, I love the directors," Buffett said in a CNBC interview in April, while discussing the recent controversy over the company's executive pay plan.
He has described buying into the stock as a "huge mistake."