Stable Value
A value, with its working shown.
Stable Value is an independent estimate of what a specific car would sell for today. It always comes with three things: a range, a confidence level and a date.
- Range
- $1.18–1.36M · 80%
- As of
- 24 Sep 2026
- Evidence
- 14 comparable sales
1973 Porsche 911 Carrera RS 2.7 Touring · illustrative
Stable Value is an independent estimate, not an asking price, an offer or an appraisal.
What goes into it
Seven inputs. One range.
Each input moves the value up or down from the market for that model. The weights shown are illustrative; they vary by segment and by how much evidence exists.
Comparable transactions
Recent sales of the same model and specification, weighted by how alike they are and how recent.
Market supply
How many comparable cars are offered now, and how quickly they are selling.
Specification
Body, engine, options, colour — decoded from the chassis number and checked against the record.
Mileage
Relative to age and to comparable cars — and whether it is documented.
Condition
Graded on a five-class scale, from Concours to Project, with the evidence noted.
Provenance
Continuity of ownership, notable history, originality of major components.
Documentation
What the Vault can prove. Undocumented claims carry less weight.
How a Stable Value is built
From chassis number to range, in five steps.
- Step 1
Identify
The chassis or VIN is decoded to the exact model, variant and factory specification.
- Step 2
Find comparables
Sales from auctions, dealers and private transactions are matched and weighted by similarity.
- Step 3
Adjust
Condition, specification, mileage, provenance and documentation move the estimate from the model median.
- Step 4
Read the market
Current supply and the pace of recent sales set the direction.
- Step 5
Publish
A point estimate, an 80% range, a confidence level and the date — revised as the market moves.
Confidence and range
We say how sure we are.
When evidence is thin, the range widens rather than the number pretending to be precise.
High
Many close comparables, a documented car.
plus or minus 7 percentMedium
Fewer comparables, or gaps in the record.
plus or minus 15 percentLow
Rare car, thin market or unverified claims.
plus or minus 30 percent
What Stable Value is not
Clear about its limits.
Not an offer.
STABLE does not buy cars at its Stable Value, and no one is obliged to.
Not an insurance valuation.
Agreed values for insurance follow the insurer’s own process. A Stable Report can support it.
Not a price guide.
It values one car, with its own history — not an average for the model.
Not frozen.
Values are revised as sales complete. Every change is dated.