A Batik Air Boeing Co. 737 Max 8 aircraft, operated by Lion Air, center, sits on the tarmac at Soekarno-Hatta International Airport in Cenkareng, Indonesia, on Tuesday, March 12, 2019.

Boeing investors lost $26.6 billion in the first two trading days this week following the deadly crash of one of its popular 737 Max 8 jets in Ethiopia.

Boeing's shares slid 11 percent from $422.54 Friday to $375.41 at Tuesday's close before turning positive Wednesday morning. The share slide cut its market value from $238.7 billion to $212.1 billion over Monday and Tuesday as international aviation regulators and airlines moved to ground 737 Max jets from China to Mexico.

Its shares were up by less than 1 percent Wednesday.

Edward Jones downgraded Boeing's stock to hold from buy, noting a possible "delay in orders."

Sunday's crash of a passenger jet en route from Addis Ababa to Nairobi killed all 157 people on board. The disaster came five months after a Lion Air 737 Max 8 crashed in Indonesia, killing all 189 people aboard. The cause of the Ethiopian Airlines plane is under investigation.

The U.S. is increasingly alone in defending the American-made jets since the Federal Aviation Administration deemed the 737 Max to be "airworthy" earlier this week. The aircraft hasn't been grounded in the U.S.

