Mr. Dorsey, who will remain on Twitter’s board until its next election in 2022, stressed that he had made the decision to leave and had not been forced to go. He had recently discussed his desire to leave Twitter and to focus on projects in cryptocurrency and philanthropy, said a person familiar with his thinking who was not authorized to speak publicly.
In recent years, Mr. Dorsey has become increasingly interested in cryptocurrencies and the principle of technology decentralization. He said in 2019 that Twitter would help to build a decentralized form of social media that would allow users to set their own algorithms for promoting content and moderate their own communities rather than relying on a tech company to make those decisions.
Mr. Dorsey tapped Mr. Agrawal to oversee Twitter’s contributions to the project, known as Bluesky, which is funded by Twitter but operated independently. In August, Twitter hired Jay Graber, a cryptocurrency developer and the founder of a social events start-up, to lead Bluesky.
Mr. Agrawal, 37, is a low-profile figure who started his career at Twitter over a decade ago, as an engineer. He worked his way up through the company and was made its chief technology officer in 2017.
“Parag has been behind every critical decision that helped turn this company around,” Mr. Dorsey said in his email. “My trust in him as our C.E.O. is bone-deep.”
The majority of Mr. Dorsey’s wealth comes from Square, which he founded in 2009 during his last departure from Twitter. Last April, Mr. Dorsey announced that he would donate $1 billion, or nearly a third of his total wealth, to relief programs related to the coronavirus and other philanthropic endeavors. Mr. Dorsey has also given $15 million to guaranteed-income projects, which allow cities to provide financial support to residents in need.
Twitter’s stock jumped 5 percent on the news of Mr. Dorsey’s departure before a halt in trading.
“That’s because he was running two companies at the same time,” Mr. Hubbard said of investor reaction. “If you take the pressure off of the C.E.O to run two companies, I think the value of the company is just going to go up.”