US housing inventory growth is accelerating: The monthly supply of new single-family homes rose +1.0 month in May, to 10.3 months, the highest since February 2009. This indicator measures how many months it would take to sell all homes currently on the market at the current pace of sales. The higher the reading, the weaker the demand relative to supply. By comparison, the long-term median for this metric is ~6.0 months. Since the 1970s, 6 of the 7 times this indicator surged to current levels, the US economy was already in a recession. This comes as elevated mortgage rates and record homeownership costs are keeping buyers on the sidelines, leaving builders with growing inventories that they are struggling to clear. The US housing market has rarely been this oversupplied.