The New York private-equity firm has posted some big wins recently. Veritas and Evergreen Coast Capital, the PE arm of activist hedge fund Elliott Management, completed a $17 billion sale in February of AthenaHealth, a healthcare technology company, to Bain Capital and Hellman & Friedman. That month Veritas also agreed to buy the Houghton Mifflin Harcourt Company, an educational publisher, for approximately $2.8 billion.