The KOSPI index reached a new all-time high for the fifth consecutive trading session and recorded its 11th consecutive session of gains, surpassing the previous record of 3,407.31 set on the prior trading day. According to Korea Herald, the index closed at 3,449.62 on the day it achieved this milestone. Foreign investors purchased more than 1.7 trillion won worth of South Korean shares on that day, while retail investors sold 1.76 trillion won. Institutional investors bought 78.8 billion won, according to Korea Herald. The Korean won sharply rose against the US dollar on the same day. Blue chip tech shares gained ground on hopes for US rate cuts and expectations for the South Korean government's policy road map, according to Korea Herald.

On September 16, the KOSPI opened at 3,421.13 and traded at 3,428.88 by 9:23 a.m., according to AJU Press. On that day, foreign investors made net purchases of 176.5 billion won, and retail investors recorded net sales of 155.5 billion won, according to Asiae. Institutional investors recorded net sales of 18.8 billion won, according to Asiae. SK Hynix traded up 2.04 percent at 337,750 won on September 16, according to AJU Press, and was up 2.11 percent according to Asiae. Samsung Electronics was up 0.98 percent on September 16, and Samsung Biologics was down 0.67 percent, according to Asiae.