US briefings — Friday, September 18, 2026

S&P 500 adds 0.17% as semiconductors offset nine falling sectors

The S&P 500 added 0.17% to 7,650.50 on 18 September 2026 while nine of the eleven sectors fell, the Dow lost 0.18% and the Russell 2000 0.50%. A 2.78% gain in the PHLX Semiconductor index was worth about 26 bps of the 17 bps index move. Bitcoin rose 6.37% to US$81,170 and MSTR.US gained 16.39%, COIN.US 11.66%. XENE.US fell 30.69% after pausing Phase 3 depression enrolment on a safety review.