US stocks today: S&P 500, Nasdaq post best quarter since 2020 despite Iran war

S&P 500 and Nasdaq posted their best quarterly performance since 2020, closing Tuesday's session higher with technology among the biggest sector gainers. The S&P 500 gained 0.75 percent to 7,498.38 and Nasdaq rose 1.45 percent to 26,194.76, while Dow added 0.22 percent to 52,298.91. Traders are pricing in at least one Fed rate hike by end-2026, and geopolitical tensions around the Iran conflict continue to influence sentiment.