The Saudi state oil giant Saudi Aramco saw its shares drop by 10% as Riyadh’s stock market opened on Monday, halting trading.
The Tadawul market only allows stocks to fluctuate by 10% a day, meaning it halted trading as the market opened.
The drop came as global oil prices suffered their worst losses since the start of the 1991 Gulf War.
Other Middle East markets also fell as the new coronavirus affected global energy prices and Opec failed to make a production cut deal with Russia last week.
Boursa Kuwait shut down within 30 minutes of opening on Monday as stocks again dropped by 10%, the third such emergency halt to trading in recent days.
Earlier on Monday, coronavirus concerns led Saudi Arabia to cut off air and sea travel to and from nine countries: Bahrain, Egypt, Iraq, Italy, Kuwait, Lebanon, South Korea, Syria and the United Arab Emirates.
That comes after the kingdom earlier closed off its land borders as well.
An interior ministry official said: “Out of concern to protect the health of citizens and residents and ensure their safety, the kingdom’s government decided to temporarily suspend the travel.”
Saudi Arabia already shut down access to the holiest sites in Islam over concerns about the virus and the Covid-19 illness it causes.
The virus usually leaves people with only mild to moderate symptoms, but because it is new, experts cannot say for sure how far it will ultimately spread and how much damage it will do, both to health and to the global economy.
Worldwide, there are more than 110,000 confirmed cases, with more than 3,800 deaths attributed to it.
In the Middle East, there have been over 7,000 confirmed cases, with the vast majority in hard-hit Iran, which has seen 194 reported deaths.
Experts worry Iran may be under-reporting its cases.
The new virus has caused major economic disruptions, including in global aviation, which has helped slow demand for oil.
An Opec meeting with Russia last week failed to see countries agree to a production cut. In response, Saudi Arabia has warned it will increase its production and slash its own prices to claw back market share.
That sent oil prices into freefall, losing some 25% of their value. Stock markets in the Middle East followed suit.
The Dubai Financial Market saw stocks drop by 8.5% in a steep sell-off as it opened. The Abu Dhabi Securities Exchange dropped by more than 7%.