Shares of Union Pacific Corp. soared 10.1% in premarket trading Friday, which by themselves would lead the Dow Jones Transportation Average to outperform the broader stock market, after railroad operator said Chief Executive Lance Fritz would step down after eight years in the role. The announcement over the weekend came after urging by activist investor Soroban Capital Partners, which owns a stake of about $1.6 billion in Union Pacific. The implied price gain would add about 119 points to the Dow transports’ price. That by itself would imply a 0.8% gain in the Dow transports, while futures for the Dow Jones Industrial Average gained 169 points, or 0.5%. “While it is highly atypical for Soroban to publicly disclose our communication with a board of directors, given the Board’s prolonged inaction despite years of underperformance, we feel it is critical for the company’s future that we highlight the need for Mr. Fritz to be replaced with best-in-class leadership,” Soroban said in a letter to Union Pacific’s board that it made public on its website. Union Pacific’s stock has tumbled 21.8% over the past 12 months, while shares of rivals Norfolk Southern Corp. have dropped 13.7% and CSX Corp. have shed 10.7%, and the Dow transports have declined 3.8%.