XY - Steam Siege Ultra Rare (STS) carries a total slabbed market cap of $4.6M as of Nov 13, 2026. TCGBerg tracks a fair value for 60 card and grade combinations in the set. M Gardevoir EX #112 · PSA 10 anchors the set at 24.8% of its total cap.
Historical context
Released in 2016 as a EN release.
Market overview
Cap is concentrated: the largest card-grade position is 24.8% and the top 5 make up 66.2% of set cap. The set's cap-weighted fair-value confidence is moderate (54/100). It has seen 259 graded sales over the trailing 30 days.
Frequently asked
How much is a complete XY - Steam Siege Ultra Rare set worth?
One Near Mint copy of each XY - Steam Siege Ultra Rare card costs about $252 (the cheapest printing of each, 21 of 21 cards priced as of Nov 13, 2026). The most valuable is M Gardevoir EX #112 at $57.11.
What are the chase cards in XY - Steam Siege Ultra Rare?
Ranked by PSA 10 fair value, the most valuable XY - Steam Siege Ultra Rare cards on TCGBerg are Steelix EX #108 ($1,410.53), Gardevoir EX #111 ($1,029.34), Volcanion EX #107 ($894.13), M Gardevoir EX #112 ($823.60) and M Steelix EX #109 ($613.69).Values are model estimates from recorded sales and change as the market moves; open a card for its sales evidence and graded values.
What is included in the XY - Steam Siege Ultra Rare card list?
This list covers 21 catalog printings. Editions and finishes can have separate entries for the same card number. Prices appear where valuation or sales evidence is available; an unpriced entry does not mean the card is worth zero.
How do I compare XY - Steam Siege Ultra Rare card prices?
Match the card number, printing and condition before comparing values. Use raw condition prices for ungraded copies, and the same grading company and grade for slabs. Open a card to check the available price history, recorded sales and sales evidence.