The Nasdaq 100 has entered a new bull market, achieving its best first-quarter return since 2012 at 18.5%, driven mainly by top performers like Nvidia, Microsoft, and Apple. These ten stocks account for an overwhelming 88% of this year's gains, reflecting a significant concentration of earnings. While the Nasdaq Composite has recently gained 1.3%, it remains in recovery mode following its previous bear market, prompting investors to closely watch its key players for sustainability in this rally.