The index had fallen as low as 5,599.42. The decline in futures triggered a sell-side sidecar, temporarily suspending program sell orders without closing the entire market.
Samsung Electronics ended down 3.02% and SK hynix down 7.08%, according to Aju Press. That outlet and Yonhap link the movement to concerns about returns on artificial intelligence investments following losses in U.S. technology shares.
The 3.48% loss is the closing change; the fall of more than 5% describes a point during the session.