Method. One set, one index. The universe is every card in the set; the basket is the cards that trade as ungraded singles — at least 6 clean single-card sold comps in the trailing 30 days to enter, 4 to stay. Price-weighted on PriceCharting's dated ungraded sold list (blended eBay + TCGplayer), never asks. Caps: no card above 25% and positions above 5% never past 50% together (the Select Sector SPDR 5/50 rule) — a weight marked * is capped, and every cap is a weight in the divisor math, so applying one never moves the level. Level = Σ(sold mark × weight) ÷ divisor 25.979823; entries, exits and cap changes are logged divisor adjustments; reconstitution quarterly (first Monday of Jan/Apr/Jul/Oct, announced the Monday before). 3 of 188 cards are in the universe but not the basket — too few clean sales in the trailing 30 days at the last screen: Meganium #10, Xerneas #64, Energy Switch #115. n30 is a liquidity gate, never a volume figure (the source caps its table at 60 rows). Mega Evolution is the September 2025 base set of the Mega Evolution series (ME01) and the first with gold Mega Hyper Rares — Mega Lucario ex #188 and Mega Gardevoir ex #187 lead it. The universe is the 188 numbered slots on PriceCharting's console; published set sizes disagree, so this index makes no set-size claim beyond that. Reverse holo, Prize Pack and stamped prints are separate items and are not in this index; sealed product is not a card and is not in the universe. Bid buttons are live eBay auctions on the exact card (verified title, soonest close with bids first, refreshed every 15 minutes) — bids, not marks. An index is a measurement, not a call. How prices work · every ticker.