William A. Porter (1928-2015) was an American businessperson who, along with Bernard A. Newcomb founded the first electronic trading platform, E-Trade. After the success of E-Trade, Porter also co-founded International Securities Exchange with Marty Averbuch and became the first chairman of ISE on his 70th birthday in 1998. Porter was the former chief executive officer, board member, and chairman emeritus of E-Trade. In 2000, CNN called Porter the "forefather of online trading".