He is the chief executive officer of neurotechnology company Neuralink and the wealth manager of billionaire entrepreneur Elon Musk since 2016.
[5] According to Financial Industry Regulatory Authority records, he was terminated in 2010 for "sending correspondence to a client without management approval".
[8] According to Bloomberg News, he is not involved in daily operations of the company and that his name was listed on the filings for legal convenience.
[5] In 2018, Birchall was named as a director and executive of Boring Company—a tunnel construction services company also founded by Musk.
[6] In 2021, Birchall opposed the idea of having Igor Kurganov—a professional poker player without a financial background and an advocate for effective altruism who had quickly become close to Musk during the COVID-19 pandemic and entrusted with co-managing the foundation—handle charity requests.
As Twitter underwent massive cost-cutting under Musk, Birchall was responsible for strategizing layoffs and approving expenditures for services.
[21] Following Donald Trump's victory in the 2024 presidential elections, in which Musk was a major financial backer, Birchall has advised the Trump transition team on space policy and artificial intelligence, contributed to the formation of councils for AI development and cryptocurrency policy, and interviewed several candidates for positions at the State Department.