Shares of Opendoor have been skyrocketing of late, but the rise is just a blip when you look back long enough.Opendoor Technologies (OPEN -13.59%)stock has risen more than 500% so far in 2025. Most of that gain, however, has come in just the past three months, a period in which it is up over 1,500%! Surely this skyrocketing stock must be near its all-time highs? Not even close, which is a sign to tread with caution here.A big idea that hasn't been proven just yetThe all-time high for Opendoor's stock came i ...