In late June, SK Hynix briefly surpassed Samsung to become the top market cap in South Korea, with its stock price touching 2,987,000 won, almost hitting 3 million won per share, and everywhere you looked it was "storage is king."

Today, that line came crashing down, with Hynix closing down 14.57%, Samsung down 9.06%, and the KOSPI down 7.89%. The Korea Exchange also triggered a sell-side sidecar, halting programmatic sell orders for five minutes.

There were two triggers. One was news that Meta plans to build a cloud business and rent out its unused AI computing power; the other was a report by The Information that OpenAI has improved inference efficiency, potentially reducing some inference costs. Together, they ignited the market's worst fear: If AI can squeeze more out of existing hardware, will the demand for new chips become less urgent? Has computing power been overbuilt?

Overnight, U.S. chip stocks already took a hit: Micron fell over 10%, the Philadelphia Semiconductor Index dropped over 6%; Japan's Kioxia also fell over 13% today. Hynix was simply the one that stood highest and fell hardest in this wave.

But digging into the root cause, the most basic reason is that it had risen too much. The gains this year have been extremely exaggerated, and the market priced it as flawless. For a stock like this, the scariest thing is someone asking if it's really that perfect. The news from Meta and OpenAI provided exactly that excuse.

Has the fundamental picture collapsed? Not yet. Even amid today's big drop, some brokerages raised their target prices: IBK raised its target for Hynix to 4 million won and expects it to beat expectations for the 11th consecutive quarter. This also aligns with Micron's strong earnings report a while back. What fell today was more like the portion of the price inflated by sentiment; the business itself hasn't been hit yet.

Among all these pieces of news, there's one I take seriously: AI computing power oversupply. For now, it's just a sentimental trigger, but it points to a real issue. The entire industry is pouring so much money into building computing power and stockpiling memory. If one day we find out too much has been built and demand hasn't kept up, that's when the strongest foundation of the memory business will really start to loosen.

My position was in the red today too, and it hurts. But I won't move it for a single bearish candle driven by profit-taking and emotional selling. Is there a memory shortage today? Yes, there still is. When it's no longer short, I'll come back and tell you.