[11] While at FTX US he established the company’s regulated business operations and opened its headquarters in Chicago.
[5] In 2022 he built and managed the launch of the company’s US retail stock brokerage and trading platform.
[12][13] Harrison announced his resignation from FTX US on September 27, 2022,[14] after protracted disagreements with Bankman-Fried over formal management structure and lack of delegation of authority at the company.
[15] In December 2022, Bloomberg reported that Harrison was raising capital for a new trading technology venture.
[16] In January 2023, he closed a $5 million seed round and founded Architect Financial Technologies, a company to develop institutional-grade trading infrastructure.