<i>Putting vesting on an founder’s ownership means that the company has the right to repurchase part or all of a founder’s ownership should a founder choose to leave prior to a certain date.</i><p>No, it doesn't. Unvested stock does not belong to the putative shareholder, hence the company doesn't need to do anything to "repurchase" unvested stock. Essentially, unvested stock is stock "promised" to an employee/investor if they satisfy certain conditions. However, until such stock vests, it does not actually belong to the employee/investor (legally or otherwise). Normally, vesting conditions are simply length of employment (i.e., still be employed by the company X months from now). If the vesting conditions are met, the promised stock automatically "vests" and becomes the stock of the employee/investor.<p>A right of first refusal regarding the departing founder's <i>vested</i> stock is a very different legal provision which is also a good idea. A right of first refusal grants the company the first right to purchase the founder's shares before he attempts to sell them to a third party.