I think a professional mediator may help resolve this situation. Everyone should feel they are fairly compensated. From a technical person’s perspetive they are doing all the work. A business person often looks at a chief technical person as a key component of the overall business model. In my opinion, the most important question is will both of you do whatever is necessary to make this startup successful? A healthy cofounder relationship is essential to this. Could you have done this startup all by yourself? Remember half of a billion dollar company is better than a 100% of a broken startup. I would also encourage you to look at several Harvard business cases where there was tension between a CTO and non technical CEO. Many times a technical CEO would be moved to a CTO role. Once they sold that company, investors would be confident in them being the CEO a next time. In short, I would suggest thinking of this from a lot of perspectives before jumping to a decision. In general, a healthy cofounder relationship is critical to a startup and please resolve this now rather than later. Best of luck!