Flip a coin. While it is in the air, think about which side you want to land up. That's what you really want to do. Seriously, though, your question is reall

Flip a coin. While it is in the air, think about which side you want to land up. That's what you really want to do. Seriously, though, your question is really only something that you can evaluate. If I were you, I would evaluate the probability of it getting sold in the next N months (where N is your limit before burnout/explosion). Then go to the founders and voice your concerns. The founders obviously want you on board (potentially, they might need you). Explain to them that you're looking to exit, and discuss possible terms with them. Let them know that you're not particularly confident with the direction of the sale, and would like some quantitative numbers and timelines for the sale or sales goals. Negotiate, with them, terms of your departure. This way, you don't leave them in the lurch during a crucial time; in exchange, negotiate an exit route that still gets you some compensation (maybe if you leave in 6 months, company unsold, you still a smaller cut of the sale). I doubt they want you leaving during a sale; they brought you in for that purpose. Discuss your concerns, determine a plan, a timeline, and metrics to evaluate success/failure. In exchange for your continued efforts, make sure you have an exit plan that advantages you as well as is considerate to them.