The S&P 500 has been climbing in recent years, reaching multiple record highs, and the momentum has generally continued in 2026

The S&P 500 has been climbing in recent years, reaching multiple record highs, and the momentum has generally continued in 2026. If we look at the past three calendar years and add in the performance this year so far, the gain totals 100%. And one thing in particular has fueled this movement: investors' excitement about artificial intelligence (AI).