A Proxy and Stock Option Agreement is a legal document between a company and its shareholders that grants the shareholders the right to purchase stock at a predetermined price. This agreement outlines the conditions under which the shareholders may exercise their options and the terms of the option purchase. There are typically two types of Proxy and Stock Option Agreements: Non-Qualified Stock Options (Nests) and Incentive Stock Options (SOS). Nests are available to all shareholders, regardless of their financial status, and allow the shareholders to purchase stock at a pre-determined price on or before the expiration date. SOS are only available to certain qualified shareholders, such as executives, and provide special tax benefits. Both types of options must be exercised within the time frame established by the agreement and the option must be exercised at or before the expiration date.