Kraft Heinz, the food giant whose products include Jell-O and Oscar Mayer meats, on Thursday released a surprising batch of bad news that included a multibillion dollar write-down signaling a plunge in the value of some of its most famous brands.

In addition to the $15.4 billion write-down, Kraft Heinz said that last year it had received a subpoena from the Securities and Exchange Commission related to an investigation into the company’s accounting and controls. It also reported disappointing fourth quarter earnings that led some analysts to ask whether the company’s stringent controls on costs might be backfiring.

The company’s stock was down almost 27 percent as trading began on Friday.

Kraft’s chief executive, Bernardo Hees, said the company’s earnings fell short because it did not deliver sufficient cost savings.

“For that, we take full responsibility,” he said Thursday on a call with investors and analysts.

The huge write-down appeared to come from a shift in how consumers eat, emphasizing fresh food over processed products. The write-down reduced the value on the balance sheet of United States and Canadian operations and the Kraft and Oscar Mayer trademarks, the company said.