AppraisrAppraisr
Methodology

How the valuation model works

Collection-aware models fit to real sales, with explicit evidence limits and chronological evaluation.

In plain terms: an NFT is worth what similar ones have recently sold for. We look at thousands of real sales, work out what each trait adds to the price, and use that to estimate any item's value. Here is exactly how the model does it, step by step.

1

Hedonic regression on log-price

A ridge regression learns a price for every trait_type=value feature (plus a trait-count signal) directly from recent sales. Working in log-price keeps multiplicative trait effects linear and well-behaved.
2

Causal market context

Each historical floor proxy uses only sales available before that moment. A trailing low-price quantile and monthly time effects normalize old sales without allowing future transactions to change an earlier estimate.
3

Collection-aware comparables

Comparable similarity, regime boundaries, interaction features, and ensemble weights follow each collection's policy. Type-led, interaction-heavy PFP, land/resource, set/edition, and floor-led collections do not share one fixed similarity rule.
4

Robust trimming + bias correction

Wash trades are removed with a log-space MAD filter (per type bucket, so rare grails are never trimmed as “outliers”), then a median bias correction centers the estimate.

Price sensitivity

Scenario guidance, not a sale-probability claim

The current chart is a normalized scenario based on fair value, floor, and sale-price dispersion. Its 0–100 lines are relative price-appeal indexes—not probabilities and not promised time-to-sale. Appraisr now stores timestamped listing and floor snapshots. Measured sale probabilities will remain unavailable until listing outcomes and durations form a large enough sample for chronological validation.

How accuracy is measured

Honest, hold-out, per collection

Every collection's reported accuracy comes from a chronological 80/20 hold-out. The model trains on the older 80% and scores the later 20%; each target sale is absent from training, comparables, prior-sale inputs, and the causal floor at that timestamp. Weekly charts and recent-sale tables are immutable rows from that same evaluation ledger—not predictions recreated later with the final model.

“Accuracy” is displayed as 100 minus absolute percentage error, floored at zero. We also report median and mean absolute percentage error, ±5/±10/±20% coverage, signed bias, and separate results for floor, middle-market, and grail sales. Positive bias means the model over-predicted. Thin segments remain visible even when aggregate results look strong.

Primary value regimes

Explicit policy for every registered collection

Each registry entry declares its valuation archetype and high-value regime fields. Hard regimes keep unlike assets out of the comparable pool—for example Punk, Azuki, and Meebits Type; Opepen Set and edition structure; and Otherdeed land, Koda, and resource signals. Interaction-led policies cover major trait combinations such as BAYC Fur, Eyes, and Mouth.

The analytics table shows unique sold tokens observed in the stored sample. It does not infer total collection supply from transaction frequency.

Confidence and grails

Local evidence controls precision

Confidence is calculated per token from effective comparable count, best similarity, comparable age, regime support, recognized-trait coverage, disagreement between model components, prior-sale age, and rare-tier support. Weak evidence widens the range and can produce an explicit insufficient-evidence state. Grails use same-collection rare-tier sales first, then token history, active asks, and executable item or trait bids as bounds. Cross-collection grail multipliers are research context only and are never substituted as a token price.

Marketplace data via the OpenSea API and CryptoPunks' native market. Estimates are uncertain and are not financial advice.