The stock price of Kraft Heinz plunged 20% late Thursday after the food giant disclosed it received a subpoena from the Securities and Exchange Commission and reported a large net loss due to the reduction of goodwill in some of its best-known brands. Kraft Heinz also said in a conference call discussing earnings that it cut its quarterly dividend to 40 cents a share from 62.5 cents and that it was considering selling off some of its businesses to help pay down debt. The company reported $30.9 billion in long-term debt at the end of 2018, up from $28.3 billion...