Greenlight Capital’s portfolio, managed by David Einhorn, underwent some major changes according to the 13F SEC filing of the firm. The fund introduced stocks like AerCap Holdings N.V. (NYSE:AER), Northstar Realty Finance Corp. (NYSE:NRF), and Chemtura Corp (NYSE:CHMT). As mentioned in the 13F form, David Einhorn’s 13F portfolio registered investments of $7.18 billion as compared…