Korean stock market plunges, Iran airport ‘explosion sound’, US official says ‘missile’, Iran ‘no’ Regarding the explosion sound at the Iranian airport on the 19th, when the Korean stock market plummeted, a U.S. official said it was an “Israeli missile attack,” but an Iranian official denied it and said it was “not a missile airstrike.” The Korean stock market fell by 2.89% and SK Hynix by 5.43%..