# Treasury Yields Rise as AI-Linked Stocks Outperform in September

By Enna Lee

Canonical URL: https://www.tokenpost.com/news/investing/28948
Published: 2026-10-09T12:36:33.000Z
Updated: 2026-10-09T12:36:33.000Z
Section: Investing

> The 10-year Treasury yield climbed 54 basis points, while semiconductor stocks remained among September’s strongest performers despite pressure on other rate-sensitive assets.

The 10-year U.S. Treasury yield climbed 54 basis points in September even as semiconductor and other artificial intelligence-linked stocks remained among the market’s strongest performers, highlighting a split between rate-sensitive assets and parts of technology.

The benchmark yield rose from 4.75% on Aug. 31 to 5.29% on Sept. 30. The 10-year inflation-indexed Treasury yield also increased, moving from 2.44% to 2.93%.

The difference between the two yields widened by roughly 5 basis points, from about 2.31% to 2.36%. That suggests a comparatively limited increase in breakeven inflation, with the market pattern more consistent with higher real yields than with a broad rise in expected inflation.

The pattern is consistent with competing explanations involving growth expectations and compensation for holding long-duration assets. The available figures do not establish whether stronger expected growth, higher term premiums, fiscal risks, monetary-policy risks or supply concerns were the dominant factor.

Some U.S. fixed-income assets declined between 2.3% and 5% during the month. The equal-weighted S&P 500 Index fell 4.91%, while small-cap stocks, real estate investment trusts, utilities and financials also weakened.

Semiconductor stocks and the iShares USA Momentum ETF were among September’s strongest performers. The pattern suggests continued strength in parts of the technology market even as higher yields pressured other interest-rate-sensitive assets.

“The AI trade in financial markets was alive and well in September of 2026,” Harry Mamaysky said. Mamaysky called the month’s price action puzzling.

One possible explanation is that investors expect artificial intelligence to improve productivity and economic growth. Hyperscale technology companies are increasing spending on data centers, chips, electricity and networking, creating expectations that future earnings could offset some of the valuation pressure caused by higher discount rates.

Another explanation is that investors are demanding greater compensation for holding long-duration assets because of fiscal, monetary-policy and supply risks. A higher real yield alone does not prove that growth expectations improved.

U.S. nonfarm business labor productivity increased 1.4% at a seasonally adjusted annual rate in the second quarter of 2026 and rose 2.2% from the same quarter a year earlier. Those figures do not identify artificial intelligence as the cause of the increase.

The unresolved issue is whether AI-related revenue will spread beyond chipmakers and infrastructure suppliers to companies buying the technology. If broader corporate profits and cash flow fail to improve, higher financing costs could weigh on the investment cycle.

“We do not believe this is a bubble,” Mamaysky said.