Porsche 928
The Porsche 928 market exhibits a depreciation risk of 55.81 and an undervaluation score of 55.59, while appreciation momentum stands at 45.47. Forecasts suggest a potential upward direction with probabilities between 0.52 and 0.56 over 6, 12, and 24 months, consistently within a volatile regime. The strongest leading indicator is Real Disposable Income per Capita, showing a correlation of 0.79 with a 21-month lead.
What It's Actually Worth
Blended value of a standard 38 yr, 75k mi example, ~$23.3K now. The green line weighs confirmed auction sales most heavily (the amber dots — what cars actually hammered for), blends in fast-selling "just-missed" listings, and lightly smooths out month-to-month composition noise.
Did our model work? 58% direction calls right
Each faint amber line is a forecast we would have made at that point in the past (12-mo horizon), drawn against what actually happened (blue). Over 125 scored forecasts: 58% got the direction right, median value error ±37%.
Walk-forward: each ghost uses only data available at that date — no hindsight. Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.
Auction Scorecard gavel in range 7 in 10
We replayed 593 past auctions in this market — predicting each hammer price from market data before the sale (no hindsight). Typical miss: ±40%; the gavel landed inside our predicted range 7 in 10 of the time, and we lean slightly low on average.
| Sold | Car | Our range | Hammer | |
|---|---|---|---|---|
| 2026-08-08 | 1987 · 129k mi | $8.8K–$32.0K | $20.3K | ✓ |
| 2026-08-07 | 1986 · 104k mi | $10.2K–$37.1K | $55.0K | ✗ |
| 2026-08-04 | 1988 · 35k mi | $16.1K–$58.6K | $26.0K | ✓ |
| 2026-07-27 | 1982 · 99k mi | $10.9K–$39.7K | $14.5K | ✓ |
| 2026-07-26 | 1979 · 64k mi | $13.8K–$50.3K | $96.0K | ✗ |
| 2026-07-25 | 1990 · 7k mi | $19.6K–$71.7K | $45.2K | ✓ |
| 2026-07-23 | 1985 · 66k mi | $13.6K–$49.7K | $28.5K | ✓ |
| 2026-07-23 | 1985 · 40k mi | $15.3K–$55.8K | $9.9K | ✗ |
Live now — calling it before the gavel
We're currently tracking 8 open auctions in this market. Here's our predicted hammer range for each — check back after they close.
| Closes | Car | Source | Our predicted range |
|---|---|---|---|
| open | 1982 · 129k mi | BaT | $7.2K–$38.9K ($16.8K) |
| open | 1986 · 114k mi | ebay | $7.8K–$42.1K ($18.2K) |
| open | 1987 · 163k mi | ebay | $6.8K–$36.7K ($15.8K) |
| open | 1987 · 29k mi | ebay | $14.9K–$80.0K ($34.5K) |
| open | 1984 · 90k mi | ebay | $9.0K–$48.3K ($20.8K) |
| open | 1987 · 74k mi | BaT | $10.1K–$54.0K ($23.3K) |
| open | 1989 · 58k mi | classic | $10.6K–$57.0K ($24.6K) |
| open | 1984 · 72k mi | classic | $9.8K–$52.4K ($22.6K) |
No-lookahead: predictions are made before each auction closes; the scorecard grades confirmed sold auctions only (no-sales excluded). A modeled estimate, not a guarantee. Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.
Where We Think It's Headed
Probability and range, not a single number. Wider = less certain (not bigger gains).
| Horizon | Direction | Probability | Confidence | Past accuracy |
|---|---|---|---|---|
| 6 mo | UP | 52% | Low | 53% |
| 12 mo | UP | 54% | Low | 58% |
| 24 mo | UP | 56% | Low | 65% |
Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.
If You’d Bought in 2012
$100K invested 2012-03 → today (14.4 yrs), this car vs where else you could've put the money. Rebased to 100 at the start; the dashed line is inflation (break-even).
What This Market Follows
Specialty-car prices don't move in a vacuum. These economic indicators have historically led this market — tap one to see it shifted forward by its lead time, overlaid on the value line.
Real Disposable Income per Capita leads by about 21 months (moves with this market, correlation 0.79). Shown shifted forward 21 months so its turns line up with the market's.
Why We Think This
Current Inventory Snapshot
Comparable Markets
| Market | Undervaluation | Appreciation | Liquidity |
|---|---|---|---|
| Alfa Romeo 105 Sedan | 66 | 43 | 36 |
| Mercedes-Benz 190SL | 41 | 45 | 54 |
| BMW 2002 tii | 47 | 56 | 20 |
| Datsun 240Z | 50 | 48 | 28 |
| Datsun 280Z | 38 | 64 | 52 |
| Ferrari 308 | 36 | 50 | 52 |
| Ferrari 308 GT4 | 54 | 47 | 16 |
| Ferrari 328 | 55 | 40 | 53 |
Recent Signals & Alerts
- vin returned higher VIN relisted +$43,110 vs prior
- vin returned lower VIN relisted $-4,250 vs prior
- vin returned lower VIN relisted $-4,325 vs prior
- vin returned higher VIN relisted +$16,928 vs prior
- vin returned higher VIN relisted +$16,928 vs prior
- vin returned lower VIN relisted $-3,000 vs prior
Data-backed market intelligence, not a guaranteed prediction. Figures are modeled estimates from asking prices, sold comps, and public economic indicators; they can be wrong. Not financial advice.