3) work for big corp, have idea that can't be done small, and successfully pitch internally. Move vertically internally. Not as sexy, but much more likely to succeed if your goal is the idea.
Which is why one of the strongest criteria I have now with a company, is whether or not they would consider doing a joint deal.
You are far more likely to be treated as a peon, or someone to rob, (or beat down with lawsuits) in todays corporate climate. Most of the executive staff, is straight up sociopathic bootlickers.
I cannot tell you how many times I correctly called, major market shifts (what would now be called "disruptive") only to have it fall on deaf ears and watch some competitor rise to new heights months to a year later (and eat their lunch).