NYX may refer to: Nyx, in Greek mythology, Nyx was the primordial goddess of the night NYX (comics), an American comic book miniseries by Marvel Comics Nyx (Image Comics), a character of the Spawn (comics) comic book series. NYSE Euronext, () (formerly NYSE Group, Inc.) is a 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). Nyx, a free public-access Internet Service P… (More on Nyx)