GastrodonSteam Siege · #29/114 · Rare · 2016
“It apparently had a huge shell for protection in ancient times. It lives in shallow tidal pools.”— art by Aya Kusube
The Hoshino Verdict
Drawn from the catalog, population reports and recorded sales — no filler.
Gastrodon is card 29 of 114 in Steam Siege, released in 2016 as part of the XY series. It is a Rare card, illustrated by Aya Kusube.
PSA reports 11 graded copies, 4 of them Gem Mint 10 (CGC 1 further).
Descriptive market data, not investment advice. The Hoshino Score measures how deep, liquid, widely-traded, dear and scarce this card’s market is from sales and population records we hold. It is not a forecast, not a recommendation, and not a rating of this card as an investment.
Price by grade
What each grade’s real sales say — median of what actually sold.
Each grade is priced on the median of its own real sales — never averaged across grades, and never across printings. A 1st Edition, Shadowless or No Rarity copy is a different market from the ordinary print, so it gets its own row; where a grade holds sales of more than one printing and we cannot tell which copy sold, it is shown without a price — we abstain rather than publish the blend.
| Tier | Price | Confidence | Liquidity | Basis | Obs. |
|---|---|---|---|---|---|
| Raw (ungraded) | $0.59 | — | — | market estimate (guide) | 2 |
| PSA 8 | — | — | — | no sales on record yet · pop 2 | |
| PSA 9 | — | — | — | no sales on record yet · pop 4 | |
| PSA 10 | — | — | — | no sales on record yet · pop 4 |
Cross-market comparisons and arbitrage routes are computed within one grade — PSA 10 against PSA 10, raw against raw. A route is never built from two different grades.
Price trend
Median market price over time, plus the sale-by-sale receipts.
Daily snapshot medians · US market · raw bucket.
Recent sales
| Sold | Venue | Region | Grade | Price | |
|---|---|---|---|---|---|
| 2026-09-19 32h ago | 🇺🇸 TCGplayer guide | North America | NM | $0.61 | |
| 2026-09-15 5d ago | 🇪🇺 Cardmarket guide | Europe | NM | €0.48 · $0.56 |
The 2 most recent — confirmed sales first, then estimates; distinct price points, identical re-ingested rows count once, never stacked. Venue is the marketplace the sale actually cleared on — eBay, Goldin, ALT, Fanatics, SNKRDUNK and the rest — established from the sale’s own listing URL, its auction house, or the feed’s own declaration of the venue. A via tag names the data feed that delivered the record; the feed is never the venue. Where none of those establish a marketplace the row says venue not disclosed rather than naming one we cannot prove. Rows tagged guide are marketplace price-guide points (TCGplayer market / Cardmarket trend), not confirmed sales; rows tagged est. are inferred from a listing that left the market, not directly-recorded sales. Rows tagged recorded come from a venue that publishes no sale date — Mercari Japan publishes none — so the date shown is the day we recorded the sale, an upper bound on when it sold. The price is real either way; we do not invent a date.
See the full median-price history — 30-day, 90-day and 1-year — every move this card has made, charted.
Buy from around the world
The lowest live ask on every platform we track — cheapest first.
The cheapest live ask in every region we track — real global pricing, not just the US.
See every listing we track and the net spread — cheapest ask first, the difference after ~13% marketplace + payment fees.
Asks are what sellers want; the price above is what the market actually clears at. Pro shows both sides plus the spread net of fees.
Sold around the world
Daily market prices by region and platform — what this card actually changes hands for worldwide, kept apart from seller asks.
Markets are too thin or divergent to quote a reliable cross-border spread on this card yet.
Per-platform sold history builds as feeds report — the value above is the honest anchor we hold today.
Population reports
How many graded copies exist, and how fast that number is moving — scarcity in plain numbers.
PSA 11 graded copies
| Grade | Population |
|---|---|
| PSA 10 | 4 |
| PSA 9 | 4 |
| PSA 8 | 2 |
| PSA 7 | 1 |
CGC 1 graded copy
| Grade | Population |
|---|---|
| CGC 9 | 1 |
Population over time — No new copies were slabbed in any tier we can read cleanly in this window
| Tier | Trend | 2026-08-27 | 2026-09-20 | Change |
|---|---|---|---|---|
| PSA 9 | 4 | 4 | no change | |
| PSA 10 | 4 | 4 | no change | |
| PSA 8 | 2 | 2 | no change | |
| PSA 7 | 1 | 1 | no change | |
| CGC 9 | 1 | 1 | no change |
Every point is a real population reading taken on the date shown — first reading 2026-08-27, latest 2026-09-20 (24 days). That is the whole window we hold for this card; it is not a one-year trend and we will not present it as one. A population can only grow — a card cannot be un-graded — so where a reading came back lower than the one before it, that is a partial crawl and the series carries the higher figure forward rather than drawing a fall that never happened.
Why this matters: scarcity is a flow, not a constant. A tier whose count is climbing is getting less scarce while its price chart says nothing at all — and a tier that has not moved in weeks is holding its scarcity. Nobody else publishes this per grade.
Should you grade it?
Expected grade × daily market prices − grading fees = net value, per grader.
See the full grader ladder — chance of a 10, what a 10 and a 9 actually fetch, and the fee, expected value and ROI on every route.
Should you grade it? Every grader route, your cost basis, and Japan vs the West → · or scan a photo of your copy
Long-term outlook
Transparent scenario model from real solds, supply and demand — bands widen with time.
See where this card is projected to be in 10 years — scenario bands, every horizon, and the long-term verdict.
Scenario projection based on demand/supply trends and known catalysts. Not investment advice and not a guarantee of future prices.
More from Steam Siege
Same set, same shelf.
Frequently asked questions
Answered from the data on this page — nothing here is written by hand.
Where can I buy or sell Gastrodon (Steam Siege #29)?
You can find Gastrodon (Steam Siege #29) on Hoshino, with live listings on TCGplayer, eBay CA, eBay (US), eBay UK. Each listing links directly to the seller’s page.
Is Gastrodon (Steam Siege #29) going up or down in price?
Gastrodon (Steam Siege #29) is trending up in price. 30-day change: +12%. 1-year change: +45%. Based on live market data tracked on Hoshino.
How many Gastrodon (Steam Siege #29) have been graded?
Across PSA and CGC, 12 copies of Gastrodon (Steam Siege #29) have been professionally graded, based on population reports tracked on Hoshino.
What is the PSA 10 population of Gastrodon (Steam Siege #29)?
PSA has graded 4 copies of Gastrodon (Steam Siege #29) as Gem Mint 10, according to population reports tracked on Hoshino.
📛 Get the price badge
Embeddable price badges for Gastrodon — pick the look, copy, paste. Live global data no US-only rival can show.
Drop any of these into a listing, blog or forum signature. Each shows the live number with its honest basis — real market price with sale-count provenance, or a clearly labelled guide estimate — and updates as new sales land (cached 1 hour). Add ?theme=light for light backgrounds.
Track Gastrodon in your portfolio — free
Live value across every market we track, grade-EV on your exact copy, and alerts the second the price moves.