TD Ameritrade Acquires thinkorswim:
Thinkorswim was founded in 1999 in Chicago, Illinois. On June 11, 2009, thinkorswim was acquired by TD Ameritrade. Because of this, as of July 27, 2011, all new accounts must be opened through TD Ameritrade. Existing thinkorswim accounts will soon be transferred from clearing firm Penson Financial Services to TD Ameritrade Clearing, Inc. Existing customers can still trade on the thinkorswim desktop platform for the time being but web and mobile trading must be done on TD Ameritrade platforms. For the purposes of this site, please read our TD Ameritrade reviews as we will no longer be covering thinkorswim.
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