Methodology
Our method for TCG Bros Market Intelligence. Built for a UK shop that already runs daily catalog ingest — not a copy of anyone else’s ranking claims.
1. Ingest
Each live game pulls catalog + market USD from its licensed/public feed: Scryfall (MTG), Pokémon TCG API (PKM), YGOPRODeck (YGO). One Piece and Riftbound stay “soon” until a clean price feed exists.
2. Daily snapshots
Prices land in price_snapshots keyed by card and UTC as_of date. We keep roughly 35 days so 1d / 7d / 30d windows work. Charts and sparklines need more than one snapshot day.
3. Signals
- Movers — % change vs closest prior snapshot in the selected window, weighted by price tier (junk sub‑$1 prints are down-weighted).
- Undervalued — current price below the card’s recent mean when enough history points exist.
- Volume proxy —
|% move| × tier. This is not verified sales. TCGPlayer’s developer API is closed to new applicants; we do not invent sales bars. - Simple index — mean of set averages among ranked cards (descriptive only).
What we do not claim
No guaranteed rankings, no 14-game coverage, no financial advice, no TCGPlayer verified sales. Buy links may still open TCGPlayer product pages via affiliate/direct URLs — that is separate from any developer API.