Buick Grand National/GNX
Flagged undervalued because -61% vs 2-yr avg, -60% vs 3-yr trend, inventory -0%, and sell-through 99%.
What It's Actually Worth
Blended value of a standard 37 yr, 29k mi example, ~$46.8K 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? 68% 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 102 scored forecasts: 68% got the direction right, median value error ±38%.
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 9 in 10
We replayed 183 past auctions in this market — predicting each hammer price from market data before the sale (no hindsight). Typical miss: ±18%; the gavel landed inside our predicted range 9 in 10 of the time.
| Sold | Car | Our range | Hammer | |
|---|---|---|---|---|
| 2026-06-05 | 1987 · 88k mi | $19.6K–$64.1K | $35.2K | ✓ |
| 2026-05-09 | 1986 · 77k mi | $18.9K–$61.6K | $41.8K | ✓ |
| 2026-05-09 | 1986 · 77k mi | $17.4K–$73.7K | $41.8K | ✓ |
| 2026-05-04 | 1987 · 23k mi | $23.2K–$75.9K | $48.3K | ✓ |
| 2026-04-11 | 1984 · 60k mi | $19.9K–$65.0K | $30.0K | ✓ |
| 2026-03-23 | 1987 · 74k mi | $19.1K–$62.4K | $40.4K | ✓ |
| 2026-03-20 | 1987 · 39k mi | $22.4K–$73.2K | $60.5K | ✓ |
| 2026-03-13 | 1987 · 7k mi | $29.1K–$95.2K | $75.0K | ✓ |
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 | 1987 · 11k mi | classic | $24.8K–$115K ($53.5K) |
| open | 1987 · 34k mi | classic | $20.7K–$95.8K ($44.5K) |
| open | 1986 · 63k mi | classic | $18.3K–$84.7K ($39.4K) |
| open | 1987 · 88k mi | ebay | $17.1K–$78.9K ($36.7K) |
| open | 1987 · 109k mi | classic | $14.3K–$58.0K ($28.8K) |
| open | 1987 · 44k mi | classic | $19.5K–$78.9K ($39.2K) |
| open | 1985 · 37k mi | classic | $19.2K–$81.3K ($39.5K) |
| open | 1987 · 106k mi | classic | $13.2K–$55.9K ($27.2K) |
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 | 54% | Low | 60% |
| 12 mo | UP | 55% | Low | 68% |
| 24 mo | UP | 58% | Low | 81% |
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.
Crystal Ball — What Leading Indicators Signal
Distinct from the trend forecast above: this blends all 8 leading indicators (each at its own lead time, de-duplicated so correlated ones don't double-count) into one signal. Leading indicators are collectively signaling lower over the next ~12 months (moderate conviction — 52% of weighted drivers agree), driven mainly by Ethereum (USD) and Real Disposable Income per Capita, though Core CPI (ex food/energy) points the other way.
Are the indicators agreeing?
Each bar is one driver's current push; longer = more weight. All one side = high conviction; split = low.
If You’d Bought in 2012
$100K invested 2012-01 → today (14.5 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.
Case-Shiller National Home Price leads by about 9 months (moves with this market, correlation 0.92). Shown shifted forward 9 months so its turns line up with the market's.
Why We Think This
Current Inventory Snapshot
Comparable Markets
| Market | Undervaluation | Appreciation | Liquidity |
|---|---|---|---|
| Chevrolet Camaro Z28 (5th Gen) | 46 | 61 | 35 |
| Ford Mustang Fox Body SVT Cobra | 33 | 69 | 28 |
| Plymouth Barracuda | 43 | 70 | 26 |
| Plymouth Barracuda 'Cuda | 45 | 90 | 26 |
| Chevrolet Camaro (2nd Generation, 1970-1981) SS | 23 | 29 | 2 |
| Chevrolet Camaro (2nd Generation, 1970-1981) Z28 | 28 | 40 | 26 |
| Chevrolet Camaro 3rd Gen | 45 | 37 | 26 |
| Chevrolet Camaro 3rd Gen IROC-Z | 38 | 34 | 21 |
Recent Signals & Alerts
- vin returned higher VIN relisted +$25,900 vs prior
- price jump Median asking moved sharply (z=18.2)
- vin returned higher VIN relisted +$13,500 vs prior
- price jump Median asking moved sharply (z=251.0)
- vin returned higher VIN relisted +$7,000 vs prior
- vin returned higher VIN relisted +$13,500 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.