I just watched a really fascinating video about something very similar last night:
I got out of MTG years ago, but I like following Rudy because he is so knowledgeable about this stuff. And he made a really good point in this video. People who invest in commodities and collectibles don't necessarily want to pull their money out because at that point, their money isn't working for them. It's stagnant, doing nothing, and losing growth opportunities. Hell, even a dip in prices can mean an opportunity for profits. I feel like there's some parallels here...