Knife River Gains on WSJ Report of Activist Starboard Value Building Stake, Pushing to Explore Sale

By Elias SchisgallShares of Knife River rose after The Wall Street Journal reported that activist investor Starboard Value has built a stake in the construction company and is pushing management to explore a sale or improve its margins.Knife River's stock climbed 4%, to $53.47, after-hours Wednesda…