Buick Grand National/GNX GNX
Showing appreciation momentum: +97% vs 12-mo avg.
What It's Actually Worth
Blended value of a standard 37 yr, 15k mi example, ~$46.4K 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? 72% 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 39 scored forecasts: 72% got the direction right, median value error ±36%.
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 40 past auctions in this market — predicting each hammer price from market data before the sale (no hindsight). Typical miss: ±14%; the gavel landed inside our predicted range 9 in 10 of the time, and we lean slightly low on average.
| Sold | Car | Our range | Hammer | |
|---|---|---|---|---|
| 2025-08-16 | 1987 · 28k mi | $81.5K–$263K | $157K | ✓ |
| 2025-08-07 | 1987 · 3k mi | $97.7K–$315K | $205K | ✓ |
| 2025-05-29 | 1987 · 55k mi | $63.9K–$206K | $140K | ✓ |
| 2025-05-12 | 1987 · 2k mi | $93.9K–$303K | $230K | ✓ |
| 2025-01-30 | 1987 · 82k mi | $54.5K–$176K | $102K | ✓ |
| 2024-10-23 | 1987 · 19k mi | $71.8K–$231K | $133K | ✓ |
| 2024-09-07 | 1987 · 13k mi | $76.6K–$247K | $130K | ✓ |
| 2024-07-27 | 1987 · 15k mi | $81.2K–$262K | $100K | ✓ |
Live now — calling it before the gavel
We're currently tracking 1 open auction in this market. Here's our predicted hammer range for each — check back after they close.
| Closes | Car | Source | Our predicted range |
|---|---|---|---|
| open | 1987 · 0k mi | classic | $79.7K–$369K ($171K) |
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 | DOWN | 55% | Low | 62% |
| 12 mo | DOWN | 57% | Low | 72% |
| 24 mo | DOWN | 59% | Low | 85% |
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.
Lead Indicator Forecast
Some indicators move before this market does. Gold (futures) has historically led it by about 22 months — so its recent move implies where prices head next (dashed). The solid green line is actual value through today; the shaded path is what the lead implies.
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 higher over the next ~12 months (high conviction — 75% of weighted drivers agree), driven mainly by Gold (futures) and Effective Fed Funds Rate, though Case-Shiller Home Price 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 2010
$100K invested 2010-01 → today (16.7 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.
Trade-Weighted Dollar Index leads by about 6 months (moves against this market, correlation 0.87). Shown shifted forward 6 months so its turns line up with the market's.
Why We Think This
Current Inventory Snapshot
Recent Signals & Alerts
- vin returned higher VIN relisted +$179,840 vs prior
- vin returned higher VIN relisted +$179,840 vs prior
- vin returned higher VIN relisted +$179,840 vs prior
- vin returned higher VIN relisted +$179,840 vs prior
- vin returned higher VIN relisted +$179,840 vs prior
- vin returned higher VIN relisted +$179,840 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.