Well, I know it's just a title but generally CTO is a board level position and as such you're expected to be in charge of the technical side of the company incl

Well, I know it's just a title but generally CTO is a board level position and as such you're expected to be in charge of the technical side of the company including some strategic elements as well. At least, that's how I've always seen it and I believe this is how the other founders of this company see it too. The problem when trying to work out a fair compensation is searching for CTO salaries online tends to return only large company information and not so much startups. Same thing with stock, how do you know what is fair for a late entry co-founder? It could be anything from 25% down to 5% I guess, I simply don't know.