Kospi opens up 1.8% and regains about a fifth of Thursday's 7.57% plunge, with KB Financial and Hanwha Aerospace among big gainers

We think both risks are in the tape, and that Friday's early trading already treats them as separable. Yonhap said Thursday's drop came "amid woes over artificial intelligence (AI) trade and U.S. inflation" ^[9], and it did not apportion the fall between the two. The US session leans toward the AI half: Wall Street's broad indexes closed higher while AI and semiconductor shares fell ^[4], so whatever the September producer-price data did to rate expectations ^[3], they did not take the US indexes down. The counter-case is that the two are one trade (a higher expected policy rate cuts what long-dated AI earnings are worth today), and one session cannot pull them apart.

Friday's open is the better test. The index gained 99.77 points at the open ^[1], which is 21.9% of Thursday's 454.59-point loss from a previous close of 6,008.81 ^[2][10][12]. By 9:15 a.m. the gain was 85.62 points, or 18.8% of the loss ^[5][13], so 14.15 points had faded between the two readings ^[14].

The leadership says more than the size. KB Financial's 4.72% is about 3.1 times the index's 1.54% ^[7][5][15]. Samsung Electronics rose 1.55%, level with the index, and SK hynix rose 0.48% ^[6]. Buyers, in other words, were not paying up for the group that fell on Wall Street ^[4], and they preferred banks, whose earnings tend to hold up when rates rise. That second part is our inference. Yonhap did not say why any stock moved, and one early snapshot is thin evidence.

We would be wrong if SK hynix and Samsung closed Friday ahead of the index while KB Financial gave back its gain. That would mean Seoul's sellers were finished with AI whatever Wall Street's chip shares did. The won, at 1,340.6 per dollar and up 1.4 won from Thursday's close ^[8], moved about 0.1% ^[16], too little to add to either story.