One of the biggest reasons for a card’s sudden spike in price is due to it showing positive representation in high-performing decks in the competitive scene. This is exactly what is happening to Heavy Polymerization. This card, in particular, has been performing very well as of late and is now over 300% its previous market value.
Heavy Polymerization
Fusion Summon 1 Fusion Monster from your Extra Deck, using 3 or more monsters from your hand or field as material. You can also banish monsters from your Extra Deck as material, up to the number of monsters your opponent controls, but you lose LP equal to the total ATK of monsters banished this way, when the monster is Fusion Summoned.
Heavy Polymerization is a card that has seen a single print run in the Yu-Gi-Oh! Trading Card Game (TCG). This spell card was originally priced at just under $5 a month ago, up until the weekend of the 2025 World Championship. After the event, prices of this card practically tripled to a $12 average.
The average market trend of this card has been generally favorable since entering September. The market may have fluctuated a little over the course of the month, but the trend is generally positive. At the moment, copies of Heavy Polymerization are now at a $20 average asking price, but the market is still fluctuating back and forth.
We can easily see copies of this card pushing into the $30 price range, given the current market trend. The supply situation is also exacerbated because Heavy Polymerization has only seen one printing back in 2024. To further rub salt in the wound, Heavy Polymerization was printed as a Prismatic Secret Rare. Not only does this situation make finding a copy an even harder task, but decks running this card are doing so at 2-3 copies, further dwindling stocks on the second-hand market for interested players.
Heavy Polymerization isn’t exactly a meta-defining card, but the most recent changes to the TCG Forbidden/Limited list have definitely shifted the power balance between tournament frontrunners. Even with the Doom of Dimensions expansion coming in, Heavy Polymerization will more than likely see ample use for the immediate future of the current format.
Lunalight
The archetype that’s fully taking advantage of Heavy Polymerization is Lunalight. This colorful cast of feline monsters has not only found top cut representation in the latest World Championship but also in a fair amount of regional tournaments across the world in the most recent weeks.
One of the best advantages that Lunalight has with Heavy Polymerization is that it can allow the controlling player easy access to any of Lunalight fusion monsters in the extra deck. Even by itself, Heavy Polymerization can function without the main deck Lunalight monsters as long as the controlling player has enough lifepoints to pay for the toll.
The usual targets for Heavy Polymerization tend to be either Lunalight Liger Dancer or Lunalight Panther Dancer. This is because both of these cards require a specific Lunalight fusion monster as part of their material: Lunalight Leo Dancer for Liger and Lunalight Cat Dancer for Panther. In essence, Heavy Polymerization skips and condenses the necessary steps the controlling player has to go through to gain access to these second-level Fusion monsters (Liger and Panther).
It also helps that Lunalights have built-in tools to easily access Heavy Polymerization. Lunalight Black Sheep, Lunalight Kaleido Chick, and Lunalight Masquerade are the most popular tools in the archetype that can easily bring and keep Heavy Polymerization in rotation for the match.
D/D Support from Battle of Legends Nearing 300% Market Value