The 30-year US Treasury yield climbed four basis points to 5.44% on September 24, its highest level since 2004. The move follows repeated periods in 2026 when the yield stayed above 5%, including stretches lasting more than 12 consecutive sessions, a pattern not seen since 2007. Stronger-than-expected US growth has reduced pressure on the Federal Reserve to cut rates, while persistent inflation and higher energy costs, particularly Brent crude, have added to the upward pressure. Large fiscal deficits and heavy Treasury issuance have increased the supply of government debt, requiring higher yields to attract buyers. Portfolio manager Ed Al-Hussainy said the combined pressures are increasing the compensation investors demand for holding long-term debt. Corporate borrowing for AI infrastructure, including data centers and computing capacity, is also competing for long-term capital. Rising yields are occurring globally, with European bond markets also under pressure and German Bunds reaching multi-year highs. The 10-year Treasury yield has climbed to levels last seen around 2007, raising borrowing costs across mortgages, corporate finance and other markets. Higher government-bond yields can make equities less attractive, while existing bondholders face losses if yields rise further. Companies refinancing debt issued during the low-rate era may also face substantially higher costs, and higher Treasury yields increase US interest expenses as government debt grows.