Twitter CEO Jack Dorsey resigned on Monday, effective immediately, he confirmed in a tweet around 12 noon ET. Earlier in the morning, Twitter’s stock opened about 10% higher than Friday’s close, based on CNBC‘s reports of the resignation. After a brief halt in trading, the stock is holding steady at around US$46.

Fast facts

  • Dorsey, 45, was simultaneously the CEO of Twitter and Square, a digital payments company. He remains at the head of the latter.
  • This was Dorsey’s second stint as CEO of Twitter, the company he cofounded and led in 2006. He stepped down in 2008 and became CEO again in 2015.
  • Twitter has been embroiled in controversy over the role and limits of social media, particularly during the Donald Trump presidency. Trump was permanently banned from the platform this year.
  • Dorsey’s tenure as CEO had been questioned by investors since he cofounded Square in 2009. Square’s stock price has been trading slightly up, around 1% to 2% compared to Friday. In his resignation, Dorsey said CTO Parag Agrawal would become CEO, effective immediately.
  • The Square payments app has allowed users to buy and sell Bitcoin since 2018. In its third quarter earnings call on Nov. 5, Dorsey announced plans said, “Our focus is on helping Bitcoin to become the native currency for the Internet … We have a number of initiatives toward that goal … We’re going to be building a hardware wallet. We’re exploring Bitcoin mining, a consumer device to mine Bitcoin at home or in a business or seller businesses, in fact. We believe this focus is important. We believe it’s right.”

This story was updated and headline changed shortly after Dorsey confirmed his resignation.