US week in review — Saturday, August 22, 2026

S&P 500 ends week 1.43% lower as capital rotates out of AI hardware into biotech, gold and crypto

The S&P 500 closed the week to 21 August 2026 at 7,674.37, down 1.43%, with the Nasdaq off 2.05% and the Dow off 0.85%. Health care led all eleven sectors at +4.33% after Moderna and Merck reported positive Phase 3 data for a personalized mRNA cancer vaccine, sending MRNA.US up 129.20% and MRK.US up 12.30%. Information technology fell 3.53% as semiconductors and AI optical names sold off, with FN.US down 23.42% despite record quarterly revenue. Bitcoin rose 22.68% to US$77,258 and gold gained 6.85% to US$4,680.60 an ounce.