Valeant (VRX) shares were soaring after the market's close Thursday on news that ValueAct Capital purchased three million more share in the embattled biotech. 

Valeant shares were up 5.5% after hours and continuing to climb. At time of writing, shares were at $11.82 apiece. 

ValueAct currently holds a 4.39% stake in Valeant, according to FactSet. It is the second largest shareholder in the company, following Paulson & Co. Inc., which holds a 5.68% stake. 

Just two days prior to ValueAct's announcement, Bill Ackman's Pershing Square exited its position in Valeant completely. Shares fell more than 10% on that news, after being down more than 95% year-over-year. 

Ackman previously had insisted that Pershing remained committed to a turnaround at Valeant. Ackman's loss is about $2.8 billion in total. He will remain on the board at Valeant until the company's next board election.

Valeant has been struggling for over a year at this point. Its troubles began when short seller Andrew Left of Citron Research wrote a scathing report alleging that Valeant and Philidor, a mail-order pharmacy and one of its customers, had engaged in a scheme to improperly hike revenues.

Meanwhile, last March the company blamed its former CFO and former controller, Howard Schiller, for misstatements of earnings. Schiller left the company, but it continued to flounder.

Valeant has since been scrutinized for its alleged accounting problems and steep price hikes on drugs it acquired.

Just last week the company bought more time to pay down some of its towering pile of debt—it stands at nearly $30 billion at this point—by refinancing part of it. 

Valeant did not comment on the news.