Why Borrowing Costs Are Climbing in the US and Germany

The 10-year U.S. Treasury yield was 4.970% on Monday, Sept. 14, 2026. It slipped a little that day but stayed near recent multiyear highs. The yield is the interest rate the government pays to borrow for 10 years. Germany's 10-year yield hit a new 15-year high the same day. Wall Street Journal

That 4.970% followed a climb toward 5%. Bloomberg reported on Sept. 11 that Treasury yields were pushed toward 5% ahead of U.S. inflation data. On Sept. 13, Bloomberg reported the selloff had driven a key Treasury yield to the verge of 5%. Bloomberg

Early September was lower. On Sept. 2, CNBC reported the 10-year at 4.78%, down more than 1 basis point. A basis point is 0.01 percentage points. It had reached 4.818%. On Sept. 8, CNBC reported it had briefly risen back above 4.8%. CNBC

Trading on Sept. 14 stayed in a tight range. An undated CNBC quote page listed 4.955% at 1:16 PM EDT, with an open of 4.955% and a previous close of 4.975%. The dated Sept. 14 reports remain authoritative for the 4.970% level.

Germany moved too. CNBC reported on Sept. 11 that the German 10-year crossed 3.5% on Friday, Sept. 11, for the first time since April 2011. Quote pages put the next Monday print at about 3.52%, up 0.01 percentage points, with an open at 3.5075%, a high of 3.5544%, a low of 3.506% and a previous close of 3.5316%. CNBC

An Aug. 4 U.S. Treasury release published Aug. 5 put 10-year yields at roughly 4.6% then and 2-year yields at about 4.2%. The Fed funds target, the central bank's key rate, was 3.50%-3.75%. U.S. Treasury That release cited June inflation at 3.5% headline and 2.6% core, as measured by CPI. Unemployment fell to 4.2% in June from 4.3%. Brent oil peaked near $126 in spring 2026, then eased to the low-$70s through June. The Fed's June outlook raised 2026 core inflation to about 3.3% and cut 2026 growth to about 2.2%, with about half expecting at least one rate hike in 2026.

Pressure had built since July. On July 29, Bloomberg reported the U.S. 30-year yield hit its highest since 2007. Bloomberg

The broader context here is that bonds sold off in the U.S. and Germany together, not just in the U.S. Think of the yield like the rent for borrowing money. When rent rises in both places, families face higher mortgage rates and governments pay more to borrow.

In my view, the exact level matters more than Monday's small dip. Yields near 5% in the U.S. and above 3.5% in Germany still bite. The open question before the inflation reports flagged on Sept. 11 is whether markets fear sticky inflation or want extra pay for budget and supply risks.