Seoul Open, Minute by Minute: The Bid Went Home on October 6

09:00. The Kospi opens more than 3% lower and nobody on the floor looks surprised, which is the first bad sign. Monday's close was 6,384. Samsung Electronics and SK Hynix are marked down hard on a weekend sentence from a Shanghai conference about a Chinese DRAM maker and a cell design that has not shipped to a single customer.

Early. Foreign accounts are selling. Trimming would be a polite word for it. By mid-morning, net foreign selling on the main board will have passed 1.4 trillion won and be climbing toward 1.8 trillion.

09:47. Kospi 200 futures sit 5.08% below the previous reference of 1,006.22 and stay there for one full minute, which is all the Korea Exchange requires to pull the sell-side sidecar. Program selling gets a five-minute time-out. It is the first sidecar since August 19. Five minutes, as though a market that has decided something can be sent to its room to think about it.

09:49. The index reads 6,102.67, down 4.4%. The sidecar lifts. Nothing changes except the timestamp.

10:05. Here is what the screens will not tell you. Samsung and SK Hynix launched share buybacks on August 20 and August 24. While those programs ran, the Kospi held in the mid-to-upper 6,000s and tagged 7,003.74 intraday on October 2. Samsung's buyback finished on October 6. SK Hynix's 40 trillion won program, roughly $30 billion, is due to wrap up by mid-month. The two heaviest names in the benchmark were bidding for their own stock, and the index borrowed the confidence. When a company is the marginal buyer of its own shares, a price is a measure of its checkbook. Then the checkbook closes.

10:30. Look at the sequencing. The bid goes home October 6. The first credible headline about Chinese memory supply arrives October 10. In between there was no fresh print on AI-server demand to point to. The thing that changed was who was standing on the other side of the order book.

10:44. Below 6,000. Samsung is at 233,500 won, down 6.8%. SK Hynix is at 1.468 million won, down 8.5%. SK Square is off nearly 12%, Samsung Electro-Mechanics 8.7%, and the Kosdaq has dropped more than 4%. The retail traders who ranked in the top 1% for returns over the past month are, by Mirae Asset's count, net sellers of SK Hynix. The people who made the most money last month are working hardest to leave first.

Late morning. The Kospi is down 7.4% at 5,914, its lowest since late July and more than a third below the June peak that crossed 9,000. Samsung has lost 7.7% and SK Hynix 8.8%. From the October 2 high to this print, the benchmark has shed roughly 16% in a little over a week. Not long ago this was a country's report card on the AI boom. Today it is a price chart with a bid missing.

Midday. The contagion is already running west to east and back again. The Nikkei 225 has fallen 2.7% to about 67,200, its first session after the long weekend. MSCI's Asia-Pacific gauge is down roughly 2%, on pace for its weakest close since August. Brent sits near $105.90, a two-week high, and the dollar is close to an 18-month high, with the yen at 158.5. Japan's producer prices rose 6.8% in September, a touch below August's 7.6%, but yen-denominated import prices jumped 24.5%. The Bank of Japan meets October 29 and 30 with a currency that refuses to cooperate and a stock market that just remembered it can fall.

Afternoon. Now the part that should bother you. Wall Street futures are down 0.1%. The S&P 500 closed Monday a few points from its record. A 7% drop in a G20 benchmark is, for the moment, a rounding error on the screen that sets the world's discount rate. Seoul is where the bill for Monday's $108 billion memory selloff is being handed over, and New York has not yet looked at the check.

Before the New York open. New York will have a lot to look at before the bell. JPMorgan, Goldman Sachs, Citigroup and Wells Fargo report, with their net interest margins sitting in a world where the 10-year pays roughly 5.2%. Waller, Barkin and Collins speak. Wednesday brings September CPI, polled at 3.7% year on year, against a Fed that hiked on September 16 and has not told anyone it has finished. None of those events will mention a buyback, and all of them will rhyme with one.

Last thing. The structural lesson fits on a napkin. A buyback is a perfectly respectable use of cash. It is also a bid, and a bid has an end date printed on it. Markets that lean on a scheduled purchaser are renting a floor, and rent comes due on the day the program completes. Korea ran the experiment on a national scale, with two stocks, one quarter and a lot of foreign money watching from the doorway.

Close. The sidecar is spent, the buyback is nearly spent, and the question left is the one nobody in Seoul wants to price: who is the next buyer, and at what level did they say they would show up?