With serious slides on the year, three giant companies have seen their combined market value diminish by nearly a fifth of a trillion dollars in 2015.
Out of all the S&P 500 companies, the one that has lost the most value year-to-date is Wal-Mart. The world's largest retailer, Wal-Mart is worth a total of $193 billion. But its market capitalization has diminished by 30 percent since the beginning of the year, when Wal-Mart's stock was valued at $277 billion.
This as the company has been vexed with troubling earnings concerns. In October, the stock plunged 10 percent in a single session after the company's management cut sales and profit guidance.