Auction Retention Index – ARI
The Auction Retention Index is a good indicator of market stability.
Theoretical retention is at or around 100%, but with market turbulence, this index can greatly fluctuate.
If the index is under 100%, wholesale inventory is being transacted below the target price, meaning cars are cheaper than they normally should be.
For example, a 2018 Honda Accord should fetch $16,000 on the wholesale market, if the retention index is 92%, this vehicle is likely to bring $14,720.
After a sharp index decline, a period of recovery is usually witnessed as prices correct and the index may be higher than 100%.
There are make/model specific indexes as cars depreciate differently depending on the segment. Below is a chart showing the overall auction retention index from February 2020 to September 2020. Notice the COVID-driven sharp dip between March and May 2020.
The top 10 car makes for sale currently at U.S. auctions are:
| Make | Vehicle Count |
| BMW | 4,765 |
| Mercedes-Benz | 4,948 |
| Hyundai | 5,120 |
| Dodge | 5,548 |
| Honda | 5,676 |
| Jeep | 6,434 |
| Toyota | 9,912 |
| Nissan | 10,762 |
| Chevrolet/GMC | 18,847 |
| Ford | 24,032 |
| Total | 96,044 |
Analysis of the Auction Retention Index:
As of Sept 24, 2020.
Vehicles for Sale: 96,044
Vehicles for Sale, Buy it Now: 44,604
| Buy It Now | 100.0% | 44,604 |
| ARI < 90% | 15.1% | 6,755 |
| 90%<ARI<100% | 10.0% | 4,442 |
| 100%<ARI<110% | 29.2% | 13,007 |
| ARI>110% | 45.7% | 20,400 |
| ARI < 100% | 25.1% | 11,197 |
| ARI > 100% | 74.9% | 33,407 |
