Asian tech stocks plunge on rising US bond yields and AI spending concerns

Aug 19, 2026

Asian technology and semiconductor stocks plunged on August 19, 2026, as surging US Treasury yields and rising oil prices rattled global markets. South Korea's Kospi index fell 5.8%, with chip giants Samsung Electronics and SK Hynix dropping 7.82% and 9.75% respectively. The selloff reflects growing investor anxiety over whether massive, debt-financed Big Tech investments in artificial intelligence infrastructure can generate sufficient returns in a high-interest-rate environment.

Asian semiconductor stock selloff

▪The Hong Kong Hang Seng Tech Index slumped 1.2 percent on August 19, 2026, led by declines in Baidu following weaker revenue reports.
▪On August 19, 2026, Shanghai's Star Market 50 index tumbled 6.9 percent and Shenzhen's ChiNext gauge plunged 6.3 percent.
▪Samsung Electronics shares plunged 7.82 percent to 247,500 won and SK Hynix shares tumbled 9.75 percent to 1.5 million won on August 19, 2026.
▪The South Korean bourse operator activated a sell-side sidecar on August 19, 2026, suspending program trading in KOSPI-listed shares for five minutes after the KOSPI 200 futures index fell 5 percent or more for at least one minute.
▪Japan's Kioxia Holdings dropped as much as 11 percent and Taiwan Semiconductor Manufacturing Co. fell nearly 2 percent on August 19, 2026.
▪The South Korean benchmark Kospi index fell 5.8 percent, or 398.66 points, to close at 6,471.17 on August 19, 2026, after touching an intra-day low of 6,400.81.

Rising US Treasury bond yields

▪US Treasury yields rose as the Trump administration accelerated bond issuance to finance fiscal deficits and technology hyperscalers ramped up debt sales.
▪The benchmark 10-year US Treasury yield climbed above 4.7 percent on August 18, 2026, approaching its highest level since early 2025.
▪The yield on the 30-year US Treasury bond touched 5.34 percent on August 18, 2026, reaching its highest level since 2007.
▪Brent crude traded above $91 a barrel and West Texas Intermediate crude hovered around $85 a barrel amid a diplomatic stalemate over the US-Israel war on Iran.

AI infrastructure spending concerns

▪Investors are questioning whether massive investments in artificial intelligence infrastructure will generate sufficient returns as rising capital costs pressure tech valuations.
▪An analysis by Wall Street Journal estimated that nine major technology companies hold approximately $3 trillion in off-balance-sheet commitments, largely tied to data-center leases and chips.

Big Tech debt financing pressures

▪Increased debt financing by major technology companies to expand computing capacity has made the artificial intelligence sector highly sensitive to rising interest rates.
▪A Reuters analysis reported that heavy borrowing by artificial intelligence hyperscalers to fund infrastructure has become a key factor pushing up global bond yields.