It's very difficult to follow all of the price trends in any TCG, especially when cards begin to move for reasons other than gameplay or collectibility. It appears that a buyout is massively spiking the price of an Illustration Rare on the secondary market.
The Market is Moving Again

Just last week, there was an anomalous purchase rate of Slither Wing Illustration Rare (AR) cards over at TCGplayer. On February 26th, 66 copies of the AR were sold at a $7 average. Come the following weekend (March 2nd to 3rd), we see a rapid price jump where it’s now plateauing at a $21 average.
The reason for the sudden shift in the market trend can be baffling. Perhaps competitive players have found some strategy and are capitalizing on Slither Wing’s low cost to prepare for the upcoming yearly rotation? This is unlikely.
But if that were the case, why not just go for Slither Wing’s more common variant -which is sitting at less than a dollar- for testing? Perhaps this is just another situation where scalpers are buying out certain items to artificially raise their cost before selling them at profit? It wouldn’t be the first or last time this is happening.
Slither Wing, a Study
Giving the card a fair shake, we took a closer look at the ancient insect Pokémon to see if there was more to this. And surprisingly, there is some merit to Slither Wing’s capabilities.
It’s a basic Pokémon, meaning that even if it gets knocked out, it only nets your opponent a single prize card out of the six needed to win the game. It has a rather average health pool where it’s not easily beaten down, but something with enough firepower at stage 1 or even the hardier basic Pokémon can knock it out easily.
But where it shines is in its attacks. Slither Wing’s one energy attack can be negligible. A mill does little to change the board state depending on the situation. But the Pokémon’s Burning Turbulence attack is surreptitiously devious.
For just 2 fighting energy -which can easily be searched out with something like Earthen Vessel-, Slither Wing deals pretty astronomical damage. Even if it’s hitting other Pokémon with innate resistance to fighting type, the afflicted Burn either finishes the job or sets them up for a follow-up knockout.
Slither Wing does take away 90 of its own health every time Burning Turbulence is used, but the fact that it’s a basic Pokémon means that the benefit can outweigh its cost of a single prize card.
High performing Pokémon in the competitive TCG scene today are surprisingly at the mercy of Slither Wing. Miraidon ex and Fezandipiti ex just drop to a single hit due to their x2 weakness to fighting type.
Others like Dragapult ex, Gardevoir ex, Gholdengo ex, and Archaludon ex, however, can laugh off Slither Wing’s paltry 120 attack with their more robust healthpool.
There is no evidence of rogue elements acting on this sudden market movement. From what we can see from Slither Wing itself, it may actually be competitively viable.
While this may be the case, chances are that this purchase is simply a buyout. Whether insider info about future sets is being used or not is difficult to determine, but entities trying to manipulate market prices of cards are very common in the TCG industry. Be weary of buying Slither Wing for its inflated price. If a ton of these hit the market at the same time, prices will plummet, and you'll be out precious cash.