You should also consider whether you would rather prefer to keep your good friend(s) or take part in the startup. I think going into the startup will likely ri

You should also consider whether you would rather prefer to keep your good friend(s) or take part in the startup. I think going into the startup will likely risk losing that friend, at one time or another. In hindsight, I consider going into a friends' startup a negative investment on my part, and a mistake (in 20-20 hindsight) and should have preferred to continue my then current career and keep my friends as good friends and rather gone my own way with my own company. I would have made more money that way, would have finished studies earlier and had a better career than what turned out to happen. Also, cutting school to benefit a startup company, I ended up not finishing studies and being later laid off for not being "qualified" despite sacrificing my studies at the time to benefit the company. - Expect zero gratitude and zero loyalty, when greed shines in your best friends' eyes and investors ask for people to be laid off. - They went so far as to forbid me to finish my studies, and this in writing, from my by-then-ex-best-friend. So there. Greed will override most friendships. Now, I would think twice before losing or sacrificing too many of them.