Amazon (AMZN -1.93%) has been a stellar performing stock over the past few years, and its growth trajectory has taken it to a $2.37 trillion valuation at the time of this writing. Still, some investors believe there is significant upside in Amazon's stock, and that it could reach a $5 trillion market capitalization by the end of 2030. That's a 111% gain from today's levels, which would likely be a market-crushing return over the five-and-a- half-year assessment period. So, is the $5 trillion level a dream o ...