Activist hedge fund Jana Partners has revealed a 9% stake in Six Flags Entertainment and is joining forces with NFL star Travis Kelce to pressure the amusement park operator to overhaul its marketing and customer experience strategy, according to a report by Reuters.

Jana’s managing partner Scott Ostfeld unveiled the campaign at the 13D Monitor Active-Passive Investment Summit in New York, noting that Kelce – alongside consumer industry veteran Glenn Murphy and tech executive Dave Habiger – will work with Jana as part of the engagement. The hedge fund may also propose these collaborators as potential board nominees.

Six Flags’ shares jumped 17% to $25.63 following the announcement, marking a rare rally for a stock that has fallen more than 50% since its 2024 merger with Cedar Fair. The theme park group, valued at roughly $2.6bn, has struggled this year amid weak visitor numbers and weather-related disruptions.

Kelce, who has described himself as a “theme park superfan,” adds an unusual celebrity twist to Jana’s activist playbook. The Kansas City Chiefs tight end is expected to leverage his marketing and brand influence as part of a broader strategy to boost attendance and refresh the company’s public image.

The move comes as Six Flags faces mounting activist attention. Just last week, the company added a board member linked to Sachem Head Capital Management, another well-known activist hedge fund.