<prompt> Human: I have 3.5 years of experience in engineering and I am switching companies.I am in a large company right now. Its a very safe place to work in terms of career stability. Im also in a very good area, working a very good schedule 94 schedule.My old colleague reached out to me to join his startup. He promises a lot of upside. What he said could happen is that I could be right in the middle of the action as this company blows up. I dont doubt him because hes legitimately smart, charismatic, has a good track record, and has a well off, self made dad backing him as they work in the same industry.He offered and I accepted 80k, but I feel I can get 85k as I would be moving from a very safe situation into a somewhat risky one. My leverage is that I am a young, certified professional, and I feel like I would be the first big domino for this fledgling company. The reason I accepted his offer in just a few days was because I was impulsive and he was very convincing. I feel like if I waited a few more days, he would have bumped up his offer.I know it is not within good negotiating etiquette to come back to the table after accepting an offer, but I feel bad about not getting as much as I could have if I only had waited a few more days. What should I do?  <response>: What everyone else said here: dont do it. You came to an agreement, and of you go back on it now thats unfair to the other party. 