Ten years after the financial crisis, the central question of what explains the rise and fall in house prices remains unresolved. We provide a unified framework to examine four excess credit supply variables and three speculation variables that have been proposed in the literature. Credit supply variables, particularly subprime share and worse originator share, strongly relate to future zip-code-level house price changes in the boom and bust, whereas none of the speculation variables consistently relate to house prices within MSAs. Pre-trends, supply elasticity, and depressed areas suggest these relations are not driven by lenders anticipating house price growth.