On Monday, the JPMorgan Chase (JPM) chief became the latest in a list of high-profile defectors from the Future Investment Initiative, scheduled to take place in Riyadh starting October 23rd. JPMorgan declined to specify why Dimon wouldn’t be in attendance, but institutions and individuals as varied as The New York Times and Uber Chief Executive Dara Khosrowshahi have pulled out citing concerns over the recent disappearance of Saudi journalist Jamal Khashoggi.

Khashoggi, a royal adviser turned government critic and journalist, went missing earlier this month after visiting the Saudi consulate in Istanbul, Turkey. Turkish authorities believe he was killed in the building and his body removed. The Saudi government denies this claim.

The Future Investment Initiative is designed to showcase Saudi Crown Prince Mohammed bin Salman’s Vision 2030 plan, which is highly dependent on foreign investment. Oil futures were up and Saudi Arabian stock market was down early Monday over rising insecurity in the wake of Khashoggi’s disappearance.

President Trump promised “severe punishment” if it was found that the Saudi Arabian government was responsible for the death of Khashoggi, a U.S. resident. As of Friday, U.S. Treasury Secretary Steve Mnuchin was still planning to attend the conference.