XY - Steam Siege (STS) carries a total slabbed market cap of $8.2M as of Nov 13, 2026. TCGBerg tracks a fair value for 169 card and grade combinations in the set. Gardevoir EX #116 · PSA 10 anchors the set at 21.6% of its total cap.
Historical context
Released in 2016 as a EN release.
Market overview
Cap is concentrated: the largest card-grade position is 21.6% and the top 5 make up 56.3% of set cap. The set's cap-weighted fair-value confidence is low (38/100). It has seen 406 graded sales over the trailing 30 days.
Frequently asked
How much is a complete XY - Steam Siege set worth?
One Near Mint copy of each XY - Steam Siege card costs about $433 (the cheapest printing of each, 116 of 116 cards priced as of Nov 13, 2026). The most valuable is Gardevoir EX #116 at $113.
What are the chase cards in XY - Steam Siege?
Ranked by PSA 10 fair value, the most valuable XY - Steam Siege cards on TCGBerg are Volcarona #15 (Reverse Holo) ($5,400.00), Mankey #52 (Reverse Holo) ($2,180.94), Gardevoir EX #116 ($2,180.58), Hydreigon #86 (Reverse Holo) ($2,024.11) and Azumarill #77 (Reverse Holo) ($1,912.44).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 card list?
This list covers 225 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 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.