SPY is trading at $767.36 (-0.69%) as the expiration of the U.S.-Iran ceasefire and President Trump’s refusal to extend it increased geopolitical and energy-supply concerns.

  • The S&P 500 declined on August 18, 2026; Brent crude moved above $90, reviving inflation fears.
  • Technology and semiconductor shares led the retreat.
  • The 30-year Treasury yield reached its highest level since 2007, pressuring growth-stock valuations and broad equity multiples.