Ask HN: Advice on fair ownership percentage for a non-typical new venture
I've developed a product from within Company A, while being a typical employee. I am the only person at Company A with the knowledge to both have built and to drive the product. The idea was mine originally, but that's irrelevant given I am an employee. The product has become a critical business component, and over the last two years, it has become obvious that it could stand on its own ground as a spin-off business. This idea has been tested, and Company A has invited Company B to co-own the product in a joint program. So, currently the ownership of the product is 50% Company A and 50% Company B, with both as primary and sole users of the product. I am still an employee of Company A, technically. Both companies have funded development of this project 100% while I take a market rate salary.
All parties (Comps A/B and myself) with interest in moving forward would like to now properly start up this product into a company on its own right. It has been recognized that I will receive some portion of ownership in this company, and that I will be CEO/CTO, dependent on arrangement. (Likely the former) It's also recognized that the company now includes myself as a shareholder/ownership partner. There may be one/two additional junior ownership partners introduced at this stage, but my concern is working out the details with the two primary owners (my employer and Company B) at this point. I expect to retain my market rate salary going forward, albeit as an employee of new company.
My question is: Assuming I am the primary intellectual capital behind this venture (both in the past and going forward as we look to grow this as a real business), what, in your mind, would be a fair ownership split?