Analyst Jay Goldberg has issued a sell rating on Nvidia, raising concerns about a potential AI-driven stock bubble reminiscent of the dot-com era. Goldberg, the only analyst among 80 to take this stance, points to overvaluation and uncertain returns on tech firms' significant capital expenditures. Nvidia's market cap of $4.5 trillion is under scrutiny, with parallels drawn to the 1990s telecom infrastructure overbuild, where excessive spending led to a market crash.