[U.S. Market Brief] Why Oracle Gained While 30-Year Yields Hit 24-Year Highs

New York markets closed lower for the fourth straight day on September 29: the Dow fell 0.26%, the S&P 500 declined 0.16%, and the Nasdaq Composite dropped 0.09%. The selloff, though, was more of a tremor than a shock. The real story unfolded in bonds. The U.S. 30-year Treasury yield climbed to 5.62% intraday—its highest level in 24 years.

Meanwhile, semiconductor and AI-related stocks diverged by name. Oracle held momentum from a 7% surge in the four prior trading sessions, while Marvell Technology rose over 4% after analysts raised their price target to $330. As yields climbed, individual names moved in different directions—a dynamic that could easily bleed into Korean equities today.

U.S. market heatmap (S&P 500 sectors) from overnight—green indicates gains, red indicates declines (finviz.com)

Three major indexes lower for fourth day, yet declines narrowed

The Dow closed at 51,349.92, down 131.59 points (0.26%), the S&P 500 finished at 7,670.84 (down 0.16%), and the Nasdaq Composite ended at 26,797.54 (down 0.09%). Monday's losses were steeper: −0.67%, −0.77%, and −0.92% respectively. Selling pressure eased noticeably in a single day.

Two forces moved markets. The first was long-duration Treasury yields, which took center stage. The second was murkier news filtering out of the AI sector. Anthropic's IPO filing surfaced online, revealing the company aims for a $2 trillion valuation. Yet the startup posted a $42 billion net loss last year. Worse, the filing itself acknowledges its AI models could pose an "existential threat" to humanity. On a day when AI valuations faced renewed skepticism, the combination unsettled sentiment.

New York Stock Exchange (NYSE)

Semiconductors split—Oracle and Marvell advance; valuation headwinds persist

Semiconductor and AI infrastructure stocks tied to Korean exports showed sharp divergence. Oracle extended gains from a 7% rally through the prior four trading sessions, while Marvell Technology climbed 4.34% after an analyst raised its price target to $330.

Yet across the broader tape, Anthropic's leaked IPO filing dented sentiment toward AI names. The company disclosed it plans to spend $518 billion on cloud and infrastructure investment alone—a figure that demands perpetual revenue growth at a geometric pace to justify. Chip demand itself remains intact, but the question "Does this valuation math work?" resurfaced in trader conversations.

AI semiconductor chip

Treasury yields at 5.24% (10-year); 30-year at 24-year high

The 10-year Treasury yield held near 5.24% while the 30-year climbed to 5.62% intraday, marking its highest point since 2002. The move marks six consecutive days of gains. Multiple pressures aligned to push yields higher:

Driver	Mechanics
Energy costs	Middle East tensions prop crude higher, rekindling inflation fears
Fiscal weight	Large Treasury issuance volumes strain demand dynamics
Extended tightening	Market pricing that the Fed will keep rates higher for longer

The pattern differs sharply from the typical "growth weakens, so the Fed cuts rates" narrative. Instead, stagflationary pressures—persistent prices coupled with prolonged monetary restraint—are lifting long-duration yields. In such regimes, the divergence between rate-sensitive growth names and earnings-anchored value names tends to widen.

Federal Reserve headquarters

Oil fell—offsetting some inflation pressure, but not stopping the yield climb

WTI crude fell to $88.94 per barrel, down 4.66%, reversing recent geopolitical-driven strength. The dollar-yen pair edged lower to 157.27 yen, off 0.07%.

The pullback in oil loosens some inflation headwinds. Yet Treasury yields live on multiple currents, not crude prices alone. Fiscal and monetary concerns run parallel. So the decline in oil did not translate into a meaningful yield pullback.

Oil drilling platform

Asian equities overnight—China bounces on stimulus hope; Japan sags on dividends

Shanghai Composite closed at 3,830.45, up 0.18%, as Chinese officials signaled new measures to stabilize real estate and bolster employment and incomes. Bargain-hunting stepped in, though profit-taking ahead of the October 1-7 Golden Week holiday capped gains.

Japan's Nikkei 225 fell 0.60% to 65,481.27 yen, weighed by ex-dividend cutoffs from March and September fiscal-year companies and a 3.35% plunge in SoftBank Group after its Arm Holdings affiliate tanked stateside. Tokyo Electron and Sony, however, managed modest gains of 2.13% and 1.41% respectively, signaling resilience in pockets of semiconductors and electronics.

Taiwan's Taiex fell 0.82% to 47,631.96 as U.S. weakness radiated across the region. Separately, TSMC announced plans to build a wafer fab in Texas.

Korea Exchange (KRX)

What to watch in today's Korean market

Start with Korean Treasury yields. Both the 3-year and 10-year bond rates jumped overnight to four-year highs, tracking U.S. long-duration moves. Expect continued sensitivity to American yields if the overseas climb persists. Watch rate-sensitive names—growth, biotech, and secondary battery stocks—closely.

Next, semiconductors. U.S. markets saw AI-related shares diverge by individual merit. Samsung Electronics and SK Hynix could react more to company-specific tailwinds today—HBM order news or foundry updates, for example—than to broad index movement. The question is whether the gap between stocks with fresh earnings or contract wins and those burdened by valuation concerns widens here too.

Lastly, watch the calendar. U.S. September employment data arrives later this week. Stronger-than-expected jobs growth could reignite expectations for prolonged Fed restraint—and higher yields. Weaker figures might ease rate pressure. That employment report is the next key juncture.

The takeaway

Overnight, the headline declines in the three major U.S. indexes were modest. Beneath the surface, two undertows collided. One was the 30-year Treasury yield, now at its highest point in 24 years. The other was fresher doubt about AI valuations. Oil fell, easing inflation pressure somewhat—but not enough to reverse the yield trajectory. When the Korean market opens today, the real test is how these twin forces show up in local semiconductors and growth equities.

This article is for informational purposes and does not constitute a recommendation to buy or sell any security. Investment decisions and their outcomes remain the reader's responsibility.

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