How This Sample Is Built

Current Observation Scope

• We currently observe Mercari Japan. This site is independent and is not affiliated with Mercari.
• Only publicly visible sold-out listing surfaces are used.
• Observation is low-frequency and currently runs once per day.
• Daily observation uses 8 fixed Japanese search terms, with up to 5 search-result pages for each term.
• The sample comes from search results and is not a complete dataset.
• The exact time a listing sold is not known.
• Duplicate listings are removed where a repeated listing ID can be detected.
• Public pages do not show individual listing URLs, listing images, seller information, or raw data exports.

Update Schedule

Updated weekly after manual review. New notes are usually published by Tuesday morning U.S. Eastern Time.

Weekly notes are published after manual review. Availability can vary depending on data availability and review time.

Search Terms

• ポケカ
• ポケモンカード
• ポケモンカード プロモ
• ポケモンカード 旧裏
• ポケモンカード ex
• ポケモンカード PSA
• ポケモンカード 未開封
• ポケモンカード まとめ売り

Title Normalization

Japanese listing titles can mix card names, card numbers, promo words, condition words, grading terms, and search keywords. The project uses its own title-normalization dictionary to map listing titles toward formal card candidates when there is enough evidence.

• identified_card: a card number or clear promo identifier is available.
• identified_group: the title points to a meaningful group, but not one exact card.
• unidentified_signal: the title may be relevant but needs review.
• noise: lots, bundles, rarity-only terms, packs, or supply-like listings.

What The Numbers Mean

Observed listings are unique sold-out listings observed for a card during the weekly window, within this limited sample. Days seen is the number of days in the weekly window where that card appeared in the sample.

Activity Signal is a simple tier based on how many listings we observed and on how many days the card appeared. Current thresholds are: Very Active = at least 20 observed listings and at least 4 days seen; Active = at least 8 observed listings and at least 2 days seen; Notable = at least 3 observed listings.

Identification rate is the share of unique observed listings that were normalized to identified cards. Weeks with fewer than 5 observed days are not published as Weekly Signals.

Public And Internal Boundaries

• Titles are used for card normalization, but individual listing pages are not republished.
• Seller information.
• Individual listing URLs.
• Listing images.
• Raw data exports.
• Purchase buttons or direct marketplace calls to action.
• Prices and estimated value metrics are kept internal during the beta period.