President Donald Trump threatened "severe punishment" over the disappearance of Washington Post contributor Jamal Khashoggi.
The Tadawul exchange in Riyadh dropped over 6 percent in the week's first day of trading, with 182 of its 186 listed stocks showing losses by the early afternoon.
Turkish officials say they fear Saudi agents killed and dismembered Khashoggi after he entered the Saudi Consulate in Istanbul on Oct. 2, saying they have audio and video recordings of it that they have not released. The kingdom has called the allegations "baseless," but has offered no evidence the writer ever left the consulate.
In an interview to be aired Sunday, Trump told CBS' "60 Minutes" that the consequences of Saudi Arabia being involved would be "severe."
"There's something really terrible and disgusting about that, if that was the case, so we're going to have to see," Trump said. "We're going to get to the bottom of it and there will be severe punishment."
However, Trump in the same interview said: "As of this moment, they deny it and they deny it vehemently. Could it be them? Yes."
Saudi Crown Prince Mohammed bin Salman has aggressively pitched the kingdom as a destination for foreign investment. But Khashoggi's disappearance, and suspicions he may have been targeted over his criticism of the crown prince, has led several business leaders and media outlets to back out of an upcoming high-profile investment conference in Riyadh.