The rights and the value of preferred stock have been the subject of several Delaware court decisions. These decisions are particularly significant for understanding the importance of contractual rights as the defining attribute affecting the valuation of preferred stock. Directors' fiduciary duties are primarily to common shareholders, while obligations to preferred shareholders are primarily contractual. Preferred stocks' contractual rights, as interpreted in these decisions, directly affects the value of the preferred and the common. When common shareholders control the board, the impact on the preferred can be negative. The common may be adversely impacted when preferred shareholders, particularly venture capitalists, control the board. Some commentators have argued that, when going-concern value is less than the preferred's preference, common stockholders should be entitled to the option value of their shares.