FHFA House Price Index (HPI)
Also called HPI, house price index.
FHFA's measure of single-family house price changes, built from repeat sales and refinancings of the same homes.
It's a weighted repeat-sales index using mortgages that Fannie Mae and Freddie Mac bought or securitized, back to January 1975. Source 1 Source 2
The flagship index is seasonally adjusted and uses home purchases only. It covers conforming, conventional loans and leaves out condominiums, co-ops and multi-unit properties. Source 2
FHFA publishes it monthly and quarterly. Past values are revised as new data on older loans arrive. Source 2
It describes average price changes. It isn't an appraisal of any one home.