Samsung Electronics and SK Hynix were slammed in early trading on Tuesday after Broadcom Chief Executive Hock Tan compared AI investors to casino gamblers, feeding a fast-moving selloff across chip stocks from Seoul to Wall Street. The Kospi fell more than 7% intraday and was last down 7.1% at 5,934.47, while the Korea Exchange briefly suspended program trading to curb volatility, the first such halt in two months. The drop came as investors worried not only about stretched AI spending, but also about fresh competition from China’s CXMT and the durability of the memory upcycle.
The selloff was brutal because it hit after a long run of AI optimism, not before it. Samsung reported record earnings last week and still fell. SK Hynix, one of the biggest beneficiaries of AI demand for memory chips, slid nearly 10% in early trading. In the US, the weakness was already visible overnight, with Micron Technology retreating 3.9% and the Philadelphia Semiconductor Index falling 2.7%. The message from the market was clear: investors are no longer rewarding every AI-linked name on the promise of endless capex.
Tan delivered the comment at the DBS Asia Future Forward Conference in Singapore on Monday, Oct. 12, 2026, and his language landed like a spark in dry brush. He said, “A lot of investors have no clue what they are investing in.” He added that they “set very extreme expectations only to find out that it’s almost like they are in a casino.” The framing mattered because Broadcom sits near the center of the AI infrastructure trade, where chip demand, network gear, and hyperscaler spending have supported huge gains across the sector.
Tan also said financing may be a bigger problem than chip shortages for the AI buildout, a warning that cuts to the heart of the current rally. The industry has spent much of the past two years focused on whether it can physically produce enough advanced semiconductors. Tan’s point was more sobering: even if the chips exist, the money to keep building the AI stack may become the bottleneck. For investors, that shifts the debate from supply constraints to the sustainability of spending itself.
The tone from Broadcom’s chief matters because he is not speaking from the sidelines. His company has been a major winner in AI infrastructure, and its views carry weight with investors trying to judge whether the boom is still in an early phase or already entering the stage where expectations outrun cash flow. When a high-profile executive suggests that enthusiasm has become speculative, traders tend to react first and ask questions later.
The epicenter of the damage was Seoul. Samsung Electronics slid nearly 9% in early trading, and SK Hynix fell nearly 10%. The Kospi’s sharp drop pushed it to a level more than a third below its June record high and below its 200-day moving average, a technical sign that momentum has turned sharply negative. The Korea Exchange’s temporary program-trading suspension underscored how quickly volatility escalated. That intervention is meant to slow automated selling when moves become too violent, and this was the first such halt in two months.
The speed of the decline showed how exposed Korean chipmakers are to changes in sentiment around AI. Samsung and SK Hynix are central to the memory cycle, and their shares have been closely tied to expectations for AI-related demand. But the market now appears more willing to question how much of that future growth is already priced in. Even strong results have not protected the stocks from the broader fear that the boom could be losing some of its shine.
That concern is not just about valuation in the abstract. It is about whether the market can keep assuming that cloud giants, data-center builders and AI developers will continue to spend aggressively at the same pace. Tan’s remarks fed the impression that the answer may be less certain than investors had hoped. Once that doubt takes hold, it can hit the most crowded beneficiaries hardest, especially when they have already run far ahead of the broader market.
The slump was also amplified by a report that China’s CXMT made progress on a new memory architecture, 4F² DRAM, that Samsung and SK Hynix are also developing. That matters because it adds a competitive angle to an already crowded trade. Investors are now balancing two risks at once: the possibility that AI spending is not as durable as assumed, and the risk that rivals could erode the pricing power needed to justify current valuations.
The report does not change the longer-term strategic picture on its own, but in a market already nervous about chip valuations, it added another reason to sell first and sort it out later. For Samsung, the irony was sharp: the company had just reported record earnings, yet the stock still fell. Jung In Yun, CEO of Fibonacci Asset Management Global, summed up the pressure by saying, “Samsung’s strong earnings have been overshadowed by concerns about future competition from CXMT and the sustainability of AI spending.”
That combination is what made Tuesday’s move so severe. Investors were not reacting to one weak quarter or a single disappointing product cycle. They were repricing the idea that the AI memory trade can compound at the same speed indefinitely. When a market starts to question both demand and competition at the same time, the correction can turn violent very quickly.
The next key tests come this week with earnings from ASML and TSMC, which will help gauge how long bumper profit growth can last. Those reports matter well beyond their own shares because they are viewed as a read-through for the entire semiconductor supply chain. If the numbers and guidance are solid, they could steady nerves after Tuesday’s rout. If not, the selloff in Korean memory stocks may look less like a panic and more like the start of a broader reset.
There is also a more specific watchpoint in China. CXMT plans to roll out a new server-memory product, 4F² DDR5 RDIMM, by the end of 2026. That timeline keeps competitive pressure alive even if today’s moves are driven more by sentiment than fundamentals. For now, the market’s verdict is that AI euphoria is no longer enough to carry the trade by itself. Investors want proof that the spending can be financed, sustained and defended against rivals — and after Tuesday, they are demanding that proof with far less patience.
