Shares in PENN Entertainment spiked 9% on Thursday amid reports that Las Vegas-headquartered regional casino operator Boyd Gaming Corp. has approached PENN on a potential acquisition attempt.

The reports surfaced several weeks after activist investor Donerail Group issued a letter to shareholders calling for the sale of the company. Irked by what it described as heedless spending on the digital side, the activist group criticized PENN for investing billions of dollars into online gambling. The activist group is losing patience at PENN’s inability to produce meaningful returns from its digital segment. Prior to Thursday’s news, PENN shares had jumped about 30% since last month’s letter.

As of 6:30 p.m. ET on Thursday, PENN shares traded around $20 a share, up nearly 10% from Thursday’s close. With vast assets and operations, PENN is valued at roughly $9 billion, including debt. Boyd, which is valued at approximately $7.8 billion, including debt, is the smaller of the two. The relative size of the companies could provide complications if negotiations materialize.

News of the acquisition attempt was first reported by Reuters on Thursday. When reached by Reuters, PENN declined comment.

Last summer, PENN announced a transformative $1.5 billion deal with ESPN that led to the formation of sports betting operator ESPN BET. Under the licensing agreement, PENN gained the right to use ESPN imprimatur as its sports betting brand for a period of 10 years. The agreement contains an exit clause after three years.

PENN essentially swapped ESPN BET for Barstool Sportsbook as the company’s front-facing sports betting brand. On the same day PENN announced the deal, the company also disclosed that it sold Barstool back to Dave Portnoy at a transactional value of $1. PENN’s strategy to spend aggressively in growing its sports betting operations has drawn criticism from Donerail and other activist investors in recent months.

As a result, PENN has faced pressure to unlock long-term value with ESPN BET. Jordan Bender, an analyst at JMP Securities, wrote last month that a logical buyer would need to possess a deep understanding of the gaming environment domestically, with the balance sheet necessary to fund an acquisition. Before considering an acquisition, Bender wrote that Boyd would also need to be comfortable with PENN’s sports betting structure or determine a plan for divesting of the unit. At the time, ESPN BET maintained a nationwide market share of 4%, according to JMP’s models.

Barry Jonas, an analyst from Truist Securities, recently increased his price target at PENN from $23 a share to a share price of $25. Jonas believes that ESPN BET is primed for key product milestones in time for football season, including a revamped parlay product and newly-created links from the ESPN Fantasy Sports app. Days before the launch of ESPN BET, PENN Entertainment CEO Jay Snowden told Sports Handle he is bullish on the possibilities for cross-pollination. Essentially, the links could enable a user with A.J. Brown on his fantasy team to receive boosted odds for the receiver on the sports betting side.

Boyd has nearly 30 gaming entertainment properties nationwide, including a handful in Las Vegas. The company also owns a 5% stake in FanDuel Group. Boyd shares fell about 3% in Thursday’s after-hours session to $51.90 a share.