And though the AI excitement has primarily boosted tech stocks, the rally could spill over into other sectors, as previous episodes of narrow market breadth have translated into a larger percentage of winning stocks in the S&P 500 overall.

The bank has also lowered its estimate of recession hitting the economy this year to 25%, down from a 35% chance predicted earlier this year.

The S&P 500 could end the year at 4,500, strategists predicted, implying around a 5% upside from current levels and a gain of about 17% for the full year.