For a century, political economists have sought to understand the nature of capital. Why, for instance, is Amazon capitalized at roughly 20 times the value of General Motors? The prevailing wisdom is that there must be something ‘real’ that underpins these different values. This thinking, I argue, is a mistake. Building on the work of Jonathan Nitzan and Shimshon Bichler, I argue that capitalization is an ideology — a quantitative ritual for converting earnings into a present value. Although the ritual is arbitrary, it gives rise to astonishing empirical regularities, reviewed here.