A fair offer would be anywhere from: - 0.25% if your role was closer to a part-time adviser, following-up monthly for a few hours to advise on technical choice

A fair offer would be anywhere from: - 0.25% if your role was closer to a part-time adviser, following-up monthly for a few hours to advise on technical choices - to 20% if you worked close to full time for about a year as CTO Of course, since you forgot to negotiate anything ahead of time, you are mostly out of luck, practically speaking. There are some legal avenues you could explore, depending on whether you contributed any IP, what paperwork you signed, etc. It's time you stand up for yourself. By the way, for companies that are mismanaged (and this is clearly one of them), the likelihood of success is even lower than for your average startup, so any stock you may fight for will probably be worthless. In conclusion, I would at a minimum demand the standard 0.25-0.75% deal that any formal advisor can get. And that's an absolute minimum. In exchange for no more work from you at all. source: founder equity calculator (http://foundrs.com http://foundrs.com)