Comment by code_Whisperer

Certainly, it's all part of the negotiation. You could negotiate retaining x% of the stock (along with rules regarding stock type, splits, etc.). Another common negotiation when selling your startup would be to retain a position (e.g. lead developer, marketing manager, even CEO!) for x months or years. Or an option for right of first refusal to buy it back if your purchaser ever decides they want to sell the company (or its assets) in the future. Everything is negotiable, but you should always have a lawyer help work out the agreements and details.