US 30-year Treasury tops 5.11%, 10-year breaks 4.5% barrier; S&P 500 slides 1.24%

US 30-year Treasury yields rose to 5.11%, clearing the closely watched 5% threshold, while the benchmark 10-year note reached as high as 4.6% intraday before settling at 4.577% — breaking above the 4.5% resistance level that had capped yields for several months. The current 10-year yield sits near the top of its 52-week range of 3.35%–5.00%; the 30-year is within 4 basis points of its 52-week high of 5.15%.

The sell-off in long-duration Treasuries rippled across global equity markets. The S&P 500 finished at 7,408.50 (-92.74 points, -1.24%), the Nasdaq Composite at 26,225.14 (-410.05, -1.54%), and the Dow Jones Industrial Average at 49,526.17 (-537.33, -1.07%). Technology and semiconductor names bore the brunt: Nvidia ($NVDA) fell 4.42% and Intel ($INTC) dropped 6.18%.

Analysts attribute the yield spike to a combination of ongoing US fiscal pressures — elevated federal deficits and rising interest payments — and a renewed geopolitical risk premium following President Trump's comments on potential infrastructure strikes against Iran. Deutsche Bank analysts recommended adding hedges, citing the post-earnings season calm as a window for volatility re-entry and Middle East tensions regaining market focus.

Veteran market strategist Ed Yardeni, writing in MarketWatch, suggested that 10-year yields could approach 5% in the near term before stabilizing, characterizing that threshold as a potential entry point for both equities and fixed income. However, the path there involves near-term disruption to risk assets across markets.

South Korean markets absorbed the full impact: the KOSPI triggered a sell-side circuit-breaker for the second consecutive session on May 18, falling 4.7% intraday before staging a recovery to close up 0.31% at 7,516.04. South Korean 10-year yields rose 2.2 basis points to 4.239%, and the USD/KRW rate crossed 1,502, re-breaching the 1,500 psychological level. Foreign investors have sold Korean equities on eight consecutive sessions, accumulating over KRW 4 trillion ($2.66 billion) in net sales.

Key dates ahead: US existing home sales for April (May 22), Federal Reserve FOMC minutes release, and the US 30-year Treasury auction (late May) — each capable of shifting the yield direction materially.

Not investment advice. Verify all figures with primary sources before acting.