Stock Market Today, Sept. 21: Tech Strength Powers Nasdaq to Record Close

The Nasdaq hit a record close on September 21, 2026, gaining 2.26% to 27,122, driven by semiconductor strength and AI optimism. The S&P 500 rose 1.49% to 7,765 while the Dow gained 0.71% to 52,049. Advanced Micro Devices jumped nearly 10% and Meta Platforms soared over 11% following strong AI developments. Bitcoin surged above $87,000 for the first time since January. However, Morgan Stanley warned that further market turbulence could occur if energy prices rise and Treasury yields remain elevated.