The Beanie Baby market on eBay is useful to study because it shows much the same behavior as NFTs. Beanie Babies are non-fungible - each one is different. So there's no "market price", just lots of individual offers. On eBay, you'll see asking prices around $5000. But if you look at completed transaction info, prices are around $50. That's what an illiquid market looks like. NFTs behave the same way - high asking prices, few transactions. Such markets don't crash, they stall.