A new institutional investor has taking a liking to Barnes & Noble. Aletheia Research & Management has accumulated a 10.8% stake in the retailer, paying $137 million for 6.2 million shares. According to its filing with the Securities & Exchange Commission, Aletheia has acquired the shares “for investment purposes.” In November, Ron Burkle’s investment firm, Yucaipa Companies, acquired an 17.8% stake in B&N, an action which prompted the company to adopt a poison pill provision. B&N chairman Len Riggio remains the largest shareholder in the bookseller.