The Econoday consensus estimate for December existing home sales was 5.75 million units at a seasonally-adjusted annualized rate (SAAR). Instead, home sales fell 3.6% to 5.57 million units in a range of 5.5 million units to 5.9 million units.

Fred data on housing supply is not seasonally-adjusted and only dates to 2014. But 3.2% is a record low going back 19 years.

The NAR revised November sales from 5.81 million units to 5.678 million units so the decline was a bit bigger than reported.

Lack of supply pulled down existing home sales in December and may very well pull down sales in January as well. Existing home sales fell 3.6 percent in December to an annualized rate of 5.570 million which is near the low end of Econoday's consensus. But November, despite a small downward revision to a 5.780 million rate, remains by far the best month of the expansion, with the 5.700 million rate in March last year the next strongest.