An analysis of AI initiatives across 29 Global Systemically Important Banks (G-SIBs) from 2023 to 2025 reveals a sector in structural transition: from experimentation to scaled enterprise execution, from point solutions to platform architectures, and from model access to data control and insights as the primary source of competitive strength. JPMorgan Chase’s decade-long institutional AI build illustrates what that transition looks like at the world's largest, most interconnected and systemically important banks.