The Egyptian Exchange (EGX) lost four billion pounds at the beginning of trading session on Thursday.
The market capital lost about EGP 1.4 billion pounds on the back of the news of the disappearance of EgyptAir plane from the radar.
Financial expert Mohamed Anwar said that the Egyptian Exchange's indices were going upward on Wednesday, however the news of the missing plane turned its trends downward.
The national flag carrier has earlier said that Flight MS804 with 66 persons on board vanished from radar 10 miles after entering the Egyptian air field.
Some 56 passengers along with 10 crew members were on board the Airbus A320.
Radar lost contact with the flight at 2:45 Cairo local time while it was at an altitude of 37,000 feet.