“Memory shortage today might not be that way a year from now.”
Hock Tan, Broadcom chief executive, Singapore, October 12
At 9:47:58 on Tuesday morning in Seoul, the Korea Exchange halted program sell orders for five minutes, the first time since August 19 that its sell-side sidecar had tripped. By the close the KOSPI had lost 348.89 points, or 5.46%, to finish at 6,035.35, after dipping under 6,000 on the way. Samsung Electronics fell 7.39% to 232,000 won and SK Hynix dropped 10.09% to 1,443,000 won. Five days earlier Samsung had told investors it earned 107.4 trillion won in operating profit in the third quarter, more than any Korean company has ever made in three months.
Seoul’s trading desks had a culprit ready: ChangXin Memory Technologies, the Chinese DRAM maker that said over the weekend it would bring a denser kind of server memory to market by year-end. That is the story in nearly every account of the rout, and it is the weaker half of the explanation. The sentence that should worry anyone holding memory stocks was spoken two days later in Singapore by the head of Broadcom, which designs custom AI accelerators for OpenAI and other large buyers. The reason it matters sits in contract terms the memory makers have disclosed themselves. A rival with a product announcement cannot reprice supply that buyers have already paid deposits on. A buyer who cannot raise the money can.
How the Selling Reached Seoul
New York set it up on Monday. The Philadelphia Semiconductor Index fell 2.67% on the day, and by mid-morning Micron, SanDisk and SK Hynix had already shed about $108 billion in combined market value. Samsung and SK Hynix had already given up 4.4% and 4.5% in Seoul that day. On Tuesday foreign funds finished the job, selling a net 4.53 trillion won of KOSPI shares, with 2.36 trillion of it in SK Hynix alone and another 1.36 trillion in Samsung. The Korea JoongAng Daily, which called the session Black Tuesday, added a local detail the global wires skipped: Samsung has finished its employee share repurchase program and SK Hynix’s buyback is nearly complete, so the two steadiest bids in the market were missing just as the foreigners headed for the door.
Two Announcements, Two Different Risks
Two things were said between Saturday and Monday. They are being reported as a single bearish mood, and they describe opposite risks.
The supplier, October 10. CXMT President Cao Kanyu told an integrated circuits conference that the company plans to launch DDR5 server modules built on a 4F² memory cell by the end of the year, TrendForce reported. The design shrinks each cell from the 6F² layout the industry uses now, for a claimed 30% to 50% gain in density. Samsung has shown a 4F² prototype and is not expected to sell one before 2028. CXMT held 9.5% of DRAM revenue in the second quarter, against 39.4% for Samsung, 24.9% for SK Hynix and 23.3% for Micron.
The customer, October 12. Broadcom Chief Executive Hock Tan told a DBS conference in Singapore that “the biggest constraint” on the AI buildout might be capital, ahead of chips, memory or power. He said the industry keeps clearing its bottlenecks, and offered the line at the top of this article. Intel’s Lip-Bu Tan agreed: “If there’s any challenge in the front, it’s capital and the cost of capital.” Both men still expect demand to outrun supply for years.
The first is a supply risk with no volume attached. Cao gave no price, no yield and no shipment figure, and TrendForce’s own write-up carries the caution that commercial availability does not signal readiness for high-volume production. A company with less than a tenth of the market, describing a module it has not shipped, moved three of the most valuable chipmakers on earth. The second is a demand risk, and it comes from someone who sees the purchase orders. When an executive in that seat says the shortage may look different in a year and that money is the scarce input, he is describing the one mechanism that could loosen this market before new fabs do.
The Supply Is Already Sold
Here is what the CXMT story has to get past. Micron told analysts on September 30 that it has signed 26 strategic customer agreements covering more than 35% of its revenue through 2030, backed by $32 billion of financial commitments, most of it cash. We walked through those numbers when the stock sold off on its spending plan, and the filing behind them is blunt: Micron’s cash flow statement shows $12.7 billion of customer deposits actually received in fiscal 2026, where the same line a year earlier was empty. SanDisk’s long-term deals carry customer collateral and default penalties, and SK Hynix signed with roughly ten customers after scrapping the price ceilings that used to cap such agreements, terms we laid out in September. Buyers do not hand over collateral in a market where they expect a new supplier to rescue them within a year.
So a CXMT module arriving in December cannot touch 2027, because that volume is contracted and partly prepaid. What a credible Chinese 4F² line threatens is the period after those agreements roll off, which is roughly when Samsung’s own version is due. That is a debate about what these companies are worth in 2029, a fair thing to argue over and an odd thing to discover on a Tuesday morning. Tan’s warning is different in kind. Every deposit and guarantee in those contracts is a claim on a customer’s balance sheet, and the customers are funding themselves in private credit. Broadcom itself has been lining up more than $50 billion of debt so that OpenAI can buy its chips. If capital is the constraint, the prepayments are where the strain shows first.
Who Bought What the Foreigners Sold
The other number worth keeping from Tuesday is who was on the other side. Korean individuals bought a net 2.23 trillion won of KOSPI shares while foreigners sold for a sixth straight session. The index has now fallen five sessions in a row, which means the exit began before Cao Kanyu took the stage on October 10. Samsung and SK Hynix together account for more than half of the Korean market’s total value, so a household that owns the index through a pension or a brokerage app owns a two-stock position on memory pricing. That concentration made Korean savers rich on the way up. On the way down, it means a conference remark in Singapore and a product roadmap from China can take 5% off a national benchmark in a day.
We think Seoul sold the right stocks for the wrong reason. CXMT deserves respect: it went from 7.6% of DRAM revenue to 9.5% in a single quarter, and nobody should wave that away. But the market learned nothing new about wafers this week. What changed is that a chief executive who would know said out loud that the money might run short and the memory squeeze might ease, days after his own company was reported to be lining up $50 billion of financing for a customer. That is the risk these shares carry, and we have not seen Samsung or SK Hynix say how much of their contracted volume depends on customers who are borrowing to pay for it. They should, starting with Samsung’s final results on October 29. Until then, the lines to read are customer deposits and contract liabilities, because a buyer short of capital stops prefunding its suppliers long before it stops placing orders.