Real talk; what is the end game here?

I started getting into flipping sealed/single cards back in September. I’ve traded stocks for several years now so I enjoy the combination of nostalgia of Pokémon and the liquidity of this market right now.

Cards I purchased back in October are nearly double the price in some instances; am I the only one selling off their collections piece by piece while this market is so liquid with almost endless demand?

For my more prized cards/sealed I almost feel on edge holding this stuff as prices continue to go vertical.

I wonder what the end game is here. I cannot justify paying thousands of dollars for slabs And I imagine at some point once resellers stop selling to each other to make $10 a transaction this is going to come down to Earth.

The question is, when? If the stock market turns to shit in 2026 I could see this market imploding as everyone hoarding product makes a move for the exit.

I guess my question is, if my goal is to make some money on the side, is anyone else continuing to sell on the way up? At what point does your “investment” take up too much of your portfolio?