The Porsche 928 GTS market shows significant overvaluation at 84.2 and a moderate depreciation risk at 60.51, coupled with low liquidity at 33.03. While a downward movement has a 0.49 probability in the 6-month horizon, the 12-month and 24-month outlooks suggest an upward direction with probabilities of 0.52 and 0.54, respectively, all within a volatile regime. The strongest leading indicator is the High-Yield Bond Spread, showing a 0.78 correlation with a 21-month lead.
What It's Actually Worth
Blended value of a standard 32 yr, 72k mi example, ~$62.7K 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.
◫ 167 confirmed auction sales·117 months tracked·since 2017-02·33 active listings
Did our model work? 67% 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 52 scored forecasts: 67% got the direction right, median value error ±37%.
━ actual╱ past predictions (ghosts)
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.
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
51%
Low
62%
12 mo
DOWN
48%
Low
67%
24 mo
FLAT
50%
Low
70%
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. High-Yield Bond Spread has historically led it by about 9 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.
BECAUSE credit spreads rose 13%. THEREFORE, given its usual 9-month head start, we expect little change — about −0% (≈ −$197) over the next 9 months. Confidence: Moderate (correlation -0.60, 19 months overlap).
If You’d Bought in 2017
$100K invested 2017-02 → today (9.7 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).
━ This car $82.4K━ S&P 500 $388K━ Gold $327K━ Luxury $311K━ Housing $182K₿ Bitcoin ×69 (off-scale)
Lost ground to inflation. The Porsche 928 GTS roughly 0.8×'d your money (a real 40% LOSS to inflation). It LAGGED the stock market by about 79% — the same money in the S&P 500 would be larger. It trailed housing (-55%). (Price only — a real round-trip also loses ~10–20% to buy/sell fees and carrying costs.)
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.
High-Yield Bond Spread leads by about 9 months (moves against this market, correlation 0.60). Shown shifted forward 9 months so its turns line up with the market's.
━ Porsche 928 GTS┄ High-Yield Bond Spread, shifted +9mo
Consumer Discretionary ETF (XLY) leads by about 17 months (moves with this market, correlation 0.54). Shown shifted forward 17 months so its turns line up with the market's.
S&P 500 leads by about 17 months (moves with this market, correlation 0.53). Shown shifted forward 17 months so its turns line up with the market's.
━ Porsche 928 GTS┄ S&P 500, shifted +17mo
Dow Jones Industrial leads by about 17 months (moves with this market, correlation 0.53). Shown shifted forward 17 months so its turns line up with the market's.
━ Porsche 928 GTS┄ Dow Jones Industrial, shifted +17mo
Nasdaq Composite leads by about 17 months (moves with this market, correlation 0.53). Shown shifted forward 17 months so its turns line up with the market's.
High-Yield Bond Spread leads by about 9 months (moves against this market, correlation 0.52). Shown shifted forward 9 months so its turns line up with the market's.
━ Porsche 928 GTS┄ High-Yield Bond Spread, shifted +9mo
Advance Retail Sales leads by about 6 months (moves with this market, correlation 0.52). Shown shifted forward 6 months so its turns line up with the market's.
Bitcoin (USD) leads by about 17 months (moves with this market, correlation 0.51). Shown shifted forward 17 months so its turns line up with the market's.
━ Porsche 928 GTS┄ Bitcoin (USD), shifted +17mo
Why We Think This
Appreciation Momentum
59
Undervaluation
28
Liquidity
23
Speculation Opportunity
38
Depreciation Risk
66
Overvaluation
84
asking +157% vs historic soldasking vs historic spread
sell-through 90%sell through rate
inventory +0%inventory trend slope
asking trend +0.3%/momedian asking trend slope
sale prices +1.0%/momedian sale trend slope
171 days on marketmedian days on market
33% of listings cutting priceprice drop frequency
new-listing velocity 0% of activenew listing velocity
Current Inventory Snapshot
Active priced listings33
Median fair value$26,391
Avg deal score54/100
Recent Signals & Alerts
vin returned higher VIN relisted +$16,928 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.