Five9, Inc. has delivered a ~134% six-month price return, driven by accelerating subscription and AI revenue growth. Q2 revenue reached $312.4M (+10% YoY), with subscription revenue up 14% and AI revenue surging 78% to $39M, now 15% of subscriptions. Management raised full-year AI growth guidance to at least 60%, though some Q2 AI revenue was pulled forward from future quarters.