NYSE Euronext, Inc. ( , ) (formerly NYSE Group, Inc. and Euronext N.V.) is an American/European for-profit corporation that operates multiple securities exchanges, most notably the New York Stock Exchange (the "Big Board"), Euronext, and NYSE Arca (formerly known as ArcaEx). NYSE Group also operates NYSE Regulation, which is a non-profit Self-Regulatory Organization that oversees securities firms and companies listed on the New York Stock Exchange and NYSE Arca.