The hedge fund founded by Jeffrey Ubben has a $750 million investment in KKR (KKR), representing nearly 5% of shares, ValueAct president Mason Morfit announced at a conference Thursday.

KKR stock surged as much as 7% following Morfit’s presentation at 13D Monitor’s Active-Passive Investor Summit at New York’s Plaza Hotel.

Like several of its private equity peers that trade on the public markets, KKR is often classified by investors as a “great company, terrible stock.” KKR shares, after all, have lost 20% of their value in the past two years, though it hasn’t been a straight slide: As Morfit put it, the reputation and asset growth of the historic private equity firm “doesn’t fit with a stock that yo-yos and elevators up and down.”

“KKR is one of the oldest, most storied private equity firms in the industry,” Morfit said. And yet, KKR stock trades at just 3.5 times 2018 expected earnings. “That’s a valuation you put on a business that’s going out of business in the next three or four years,” he added.

ValueAct thinks KKR is worth $37 a share—more than double its stock price of $18 when Morfit began his presentation. KKR stock traded as high as $19 a share later in the morning. By the afternoon, KKR shares were still up more than 4%, or about $18.50 each—their highest point in nearly two years.

After taking a stake in Microsoft (MSFT) in 2013, ValueAct was credited with working behind the scenes to orchestrate a restructuring that led to the resignation of former CEO Steve Ballmer and the succession of Satya Nadella to lead the tech company. Microsoft stock has since more than doubled in value.

Not all of ValueAct’s investments have been as successful. The hedge fund has also been criticized for its controversial stake in Valeant Pharmaceuticals (VRX). ValueAct has continued adding to its position in Valeant, even as the stock has lost more than 95% of its value since 2015 amid a slew of business, regulatory, and image problems.