Thinkorswim, Inc. was founded in 1999 by Tom Sosnoff and Scott Sheridan as an online brokerage specializing in options.[2] It was funded by Technology Crossover Ventures.[3] In February 2007, Investools acquired Thinkorswim.[4]
In January 2009, it was acquired by TD Ameritrade for $225 million of cash and 28 million shares of TD Ameritrade.[5][6][7] The final sale value was $749 million and included 250,000 thinkorswim accounts.[8] At the time, thinkorswim led the industry in the number of retail option trades per day.[5] Lee Barbra was CEO.[5] In 2018, with Thinkorswim, Ameritrade became the first US retail broker-dealer to launch 24/5 trading platforms, which it did for a few exchange-traded funds through the thinkorswim platforms.[9] In early 2018, thinkorswim expanded into Hong Kong.[10]
In October 2020, Charles Schwab Corporation acquired TD Ameritrade and the thinkorswim platform became available for Charles Schwab customers.[1] Charles Schwab integrated Thinkorswim into its platform.[11]
In 2023, Charles Schwab customers were given access to thinkorswim.[1] In 2025, the thinkorswim platform added 24/5 trading on many S&P 500 and Nasdaq-100 stocks, after testing the feature as a pilot in November 2024.[12]
