Abstract: Corporate governance incentives at too-big-to-fail financial firms deserve systematic examination. For industrial conglomerates that have grown too large to be efficient, internal and external corporate structural pressures push to resize the firm. External activists press the firm to restructure to raise its stock market value. Inside the firm, boards and managers see that the too-big firm can be more efficient and more profitable if restructured via spinoffs and sales. But a major corrective for industrial firm overexpansion fails to constrain large, too-big-to-fail financial firms when (1) the funding boost that the firm captures by being too-big-to-fail sufficiently lowers the firm’s financing costs and (2) a resized firm or the spun-off entities would lose that funding benefit. Propositions (1) and (2) have both been true and, consequently, a major retardant to industrial firm overexpansion has gone missing for large financial firms. The effect resembles that of a corporate poison pill, but one that disrupts the actions of both outsiders and insiders.