U.S. stock benchmarks on Thursday ended off their lowest but still managed to log their worst daily declines in about three weeks as fears of uneven economic growth from the COVID pandemic rattled the bullish mood on Wall Street, reflected partly in the fall in long-dated Treasury yields. The Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA -2.53% declined by about 263 points, or 0.8%, at 34,418, the S&P 500 index /zigman2/quotes/210599714/realtime SPX -2.27% declined 0.9% at 4,321, while the Nasdaq Composite Index /zigman2/quotes/210598365/realtime COMP -2.23% fell 0.7% at around 14,560. All three benchmarks notched their worst single-day drops since June 18, according to FactSet data. Equity markets retreated after the latest in a string of all-time highs, with a weaker tone Thursday across global equities attributed in part to worries that the recovery from the COVID-19 pandemic could be slowed by persistent supply bottlenecks and the spread of the delta variant of the coronavirus that causes COVID-19. The 10-year Treasury note /zigman2/quotes/211347051/realtime BX:TMUBMUSD10Y -9.87% and the 30-year Treasury bond /zigman2/quotes/211347052/realtime BX:TMUBMUSD30Y -6.92% both finished at their lowest levels since around February. A jump in prices of government debt and a commensurate fall in yields has started to unsettle financial markets who fear that the hunt for haven assets may indicate uncertainty about the economic rebound from the pandemic.