Why Korea's market rout, a jump in U.S. interest rates, and the falling price of AI all belong in the same conversation
THIS MONTH'S THESIS
All year we have said the risk in this cycle is not one theatrical crash. It is a rolling repricing: money costs real money again, and every investment eventually has to pay you back. January was the structure warning. April was the borrower warning. June was the liquidity warning. July brought the same story to public markets and AI. Here is what happened in plain English — and what it means for your savings and your job.
What happened in Korea
One definition first. A circuit breaker is an automatic timeout: when a market falls too far too fast, the exchange halts trading so everyone can catch its breath. Historically, it is rare.
On July 28, Korea's KOSPI fell 10.8% and tripped a circuit breaker. Samsung fell 13.4%; SK Hynix fell 14.7%. Together they are more than half the index. The next day the KOSPI fell another 6% and tripped another breaker — the first back-to-back activation for KOSPI (the third back-to-back activation for KOSDAQ) affecting both main Korean markets. By July 30, the KOSPI was down about 34% for the month, past the prior records set in October 1997 and October 2008.
Even after all that, the KOSPI was still up roughly one-third for the year. At its June peak, it had more than doubled from year-end. That does not make a 34% monthly fall minor. It makes it a violent repricing after a parabolic run. The real question is why the market had become so fragile.
Samsung and SK Hynix make memory chips needed by AI systems. Their prices rested partly on two assumptions: memory stays scarce, and China's competitive gap lasts. Then came a report that a Chinese state-owned company had begun producing advanced chipmaking machines — perhaps five this year and twenty in 2027. They still require testing and remain well behind ASML's Dutch equipment.
The report was a spark, not the whole fire. Lofty valuations, leveraged funds, foreign selling, AI-financing worries, and — the next day — SK Hynix earnings that fell short of enormous expectations all amplified the selloff. Five unproven machines challenged an assumption in a market already primed to unwind.
That is the lesson, and it applies directly to your retirement account. When a handful of companies dominate a market, leverage crowds around them, and their prices depend on something staying true forever, you do not need proof that the story is wrong. You only need a reason to doubt.
What happened with interest rates
Same week, different continent. On July 29, the yield on the 30-year U.S. Treasury briefly hit 5.24%, the highest since 2007. That happened even after June inflation cooled to 3.5%, down from 4.2% in May.
One good inflation report did not settle the argument. June's improvement partly reflected cheaper gasoline, while renewed fighting with Iran threatened to reverse it. The Treasury still has to finance enormous deficits. And on July 29, the Fed held its policy rate at 3.5% to 3.75% while three policymakers dissented in favor of a quarter-point increase. Markets were left unsure how Kevin Warsh would respond.
Why care if you never buy a bond? The 30-year Treasury does not set every consumer rate, but long-term yields influence mortgages, corporate borrowing, and what investors demand from risky assets. They set the price of patience. That is the whole newsletter.