Tom Sosnoff is an American entrepreneur, options trader, and media personality. He co-founded the online brokerage thinkorswim in 1999 with Scott Sheridan, following a career as a market maker on the Chicago Board Options Exchange (CBOE) through the Sosnoff Sheridan Group. Sosnoff used his own capital to launch thinkorswim, which was later acquired by TD Ameritrade for approximately US$606 million in 2009.