An investment group led by Richard Schottenfeld, head of New York City-based Schottenfeld Management Corp., has acquired a 5.68% stake in Barnes & Noble.

According to a filing made with the Securities and Exchange Commission, Schottenfeld began buying B&N shares on May 29 and made his most recent purchase July 16, accumulating 4.2 million B&N shares. Schottenfeld paid between $5.32 and $6.57 per share for his stake. B&N’s shares began the year trading at $6.70, and closed at $5.65 per share on July 23.

In its filing, Schottenfeld said it purchased its stake believing B&N’s shares are “substantially undervalued and represent an attractive investment opportunity.” The filing further stated that representatives from Schottenfeld have already talked to B&N about ways to increase shareholder value, and intend to continue to hold discussions with B&N management and its board to review strategic alternatives the company might pursue.

Schottenfeld said that it currently has no specific plan or proposal for B&N other than searching for ways to boost B&N’s stock price, though it may discuss with B&N and others—such as current or prospective shareholders, industry analysts, potential strategic transaction partners, and investment and financing professional—the retailer’s “business, management, operations and capital structure.”

In an interview with the Wall Street Journal, Schottenfeld said he believes B&N can better manage its expenses while improving both its in-store and online shopping experience.

A spokesperson for B&N, which is looking for a new CEO after the surprise firing of Demos Parneros on July 3, had no comment on the Schottenfeld investment. Schottenfeld had previously held B&N shares from 2013 until August 2015, when B&N spun off its college bookstore division. That move, was one Scottenfeld had supported.