Stock market today: Dow, S&P 500, Nasdaq fall as oil rises amid US-Iran tensions, 30-year yield hits highest level in decades

Stock market today: Dow, S&P 500, Nasdaq fall as oil rises amid US-Iran tensions, 30-year yield hits highest level in decades

Grace O'Donnell · Editor, Special Projects

Updated Mon, August 17, 2026 at 11:28 PM GMT+3 1 min read

US stocks fell on Monday as oil prices and Treasury yields jumped amid renewed concerns that the US-Iran war could reignite.

The Dow Jones Industrial Average (^DJI) declined 0.5%, while the S&P 500 (^GSPC) also fell 0.5% after the benchmark index posted its third straight weekly gain. The tech-heavy Nasdaq Composite (^IXIC) dropped 0.3% following a relatively calm week on Wall Street.

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Stocks tipped lower in afternoon trading as oil prices rose on concerns about an escalation in the US-Iran war after a memorandum of understanding between the two nations expired on Monday.

Brent crude (BZ=F) futures, the international benchmark, hit $90 per barrel after President Trump said he doesn't see the war ending anytime soon. Trump also threatened Oman, telling Fox News that if the country interferes with the Strait of Hormuz, "we'll bomb the s*** out of them."

Also weighing on markets was a tightening in financial markets, with the 10-year (^TNX) and 30-year (^TYX) Treasury yields extending their gains amid concerns about growing national debt. The 30-year yield rose 5 basis points to 5.31%, hitting its highest level since June 2007.

Investors are anticipating the Federal Reserve's next policy move and a slate of retail earnings, with fewer market-moving economic data releases on the calendar. Big-box stores, including Walmart (WMT), Target (TGT), Lowe's (LOW), and Home Depot (HD), report quarterly results this week, providing insights into consumer health during the important back-to-school shopping season.

The Federal Open Market Committee meeting minutes, released on Wednesday, could offer more clues into the Fed officials' thinking.