As different classes of residential dwellings, government-subsidised Home Ownership Scheme (HOS) housing and unsubsidised private housing are aimed at adjacent groups of households on the housing ladder in Hong Kong. Subsidised housing is in high demand, and one important way of meeting it is to have better-endowed HOS families move up by buying into the private market. The paper explores the differences in price trends between these two classes of properties and attempts to find some of their determinants. Empirical analysis of historical prices of HOS and private housing reveals higher volatility in HOS prices and a differing trend with private market prices, as well as many more HOS transactions after the implementation of the White Form Secondary Market (WSM) Scheme.