From housing economist Tom Lawler:

Normally I do not send out anything about the upcoming Existing Home Sales Report until I have a sufficient number of Realtor/MLS reports to make a statistically sound projection. However, based on reports I have seen so far, it appears as if there is a very good chance that the National Association of Realtors' estimate for existing home sales in December will show a materially larger decline from November's estimate than what appears to be the "consensus" forecast. Based on the limited sample I have right now, I'd estimate (with a high standard error) that existing home sales in December as estimated by the NAR ran at a seasonally adjusted annual rate of just 5.0 million, down 6% from November's estimate. It is also likely that the YOY % change in the median existing SF home price will be below 3%.

CR Note: This is a VERY early estimate from Tom Lawler, and he will have an update (using more data) next week. Based on this estimate, December sales will the lowest level of sales since November 2015 (and that month was impacted by a regulation change),