Amid the worst start for stocks ever, one long-time buyer isstanding firm: U.S. companies. Whether that's reason for optimismis debatable.

American corporations repurchased more of their own shares inthe first four weeks of the year than they did in the same periodof 2015, according to Bank of America Corp. Goldman Sachs GroupInc. told clients this week that buybacks are accounting for nearly20 percent of trading volume, according to two people who saw thenote.

The data is subject to differing interpretations. While bullswill be glad to learn companies remain a reliable source of demandduring one of the most volatile stretches in seven years, they maybe less happy with the results. Almost $3 trillion has been erasedfrom American equity prices in 2016 as concerns ranging from Chinato the Federal Reserve spurred one of the broadest retreats fromrisk since the financial crisis.