Observed market data · immutable monthly snapshot

Birkin Resale Market Dataset & Methodology

Name: Observed Birkin Resale Market Snapshot — 2026-09
Creator: BirkinBagStock
License: https://birkinbagstock.com/terms

This dataset freezes a point-in-time observation of publicly indexed Hermès Birkin resale asking prices. It is not a transaction-price feed, market census, appraisal, authentication result, or guarantee that a listing remains available.

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4,281Observed unique listings

4,280USD-priced cohort n

$25,815Median observed ask

22Indexed merchants

21/27Sources recently observed

2026-08-09.v1Methodology version

Snapshot 2026-09 was generated 2026-09-01T01:23:08.755143+00:00. “Observed” means the listing appeared in the public index; it does not mean BirkinBagStock authenticated or independently verified the item or merchant.

What this snapshot covers

Public Hermès Birkin resale listings observed in the BirkinBagStock index at the snapshot timestamp and aggregate asking-price statistics for eligible USD rows.

It does not represent

completed transaction prices or sales volume
a census of the entire resale market
an appraisal or investment return
authentication or independent verification of an item or merchant
continued availability after the snapshot timestamp

Coverage & exclusions

Input rows	4281
Unique listing IDs	4281
Eligible USD asks	4280
Missing observation timestamp	4281
Excluded from price stats	1
Converted before ingestion	0

Rows excluded from USD price statistics can remain in observed listing counts; this prevents a missing, non-positive, non-finite, or non-USD ask from distorting price cohorts.

Methodology

Unit: one unique public listing ID at snapshot time.
Price: merchant asking price stored in USD; not a transaction price.
Deduplication: Rows are deduplicated by listing ID. If an input repeats an ID, the row with the latest available observation/update timestamp is retained with a deterministic tie-break.
Price inclusion: A row enters price statistics only when its ask is finite, greater than zero, and its reporting currency is USD.
Percentiles: P25, median, and P75 use the closest observed value at floor((n-1)*p+0.5) after ascending sort.
Cohorts: Cohort observed_n counts unique listings carrying the dimension value; priced_n counts the USD-price subset.
Completeness: Per-source scraper health is disclosed separately. Only feeds explicitly marked verified_complete have product-grade completeness evidence; observed_unverified feeds are not treated as exhaustive.
Revisions: The first successfully persisted snapshot for a UTC month is immutable. Corrections require a new methodology version and explicit publication path.

FX treatment

Some source adapters convert merchant prices to USD during ingestion and preserve original_price and original_currency. This snapshot uses the stored USD ask and does not independently refresh, reconstruct, or audit the adapter FX factor. Non-USD reporting rows are excluded.

Inclusion rule: Only positive finite asks stored with reporting currency USD are analyzed.

Source status

Source status is the latest scraper observation available at snapshot time. Observed does not mean authenticated, independently verified, exhaustive, or still available.

Verified-complete sources	11
Observed sources	21
Degraded sources	3
Error sources	3

Citation & integrity

BirkinBagStock, "Observed Birkin Resale Market Snapshot — 2026-09", methodology 2026-08-09.v1, generated 2026-09-01T01:23:08.755143+00:00, https://birkinbagstock.com/data/market-snapshots/2026-09.json.

Aggregate snapshot may be cited with attribution. Underlying merchant listing content, images, availability, prices, and terms remain subject to their source owners and must be rechecked.

SHA-256 checksum

b2932b6187e9a934824cf68d58f38215b87abec5d714298452fe68a6bd1f24ed

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