I want to know why the TF2 economy started changing crazily, but I don't know if it would be considered a valid question on this site. Should I ask it, or would it likely be closed?
Our experts in TF2 - whilst great at explaining gameplay and strategy & could probably talk about the mechanics of trading - probably don't have a complete understanding of how the TF2 Economy works and what could cause such a fluctuation.
I feel like any answer would require more than just a general understanding of Economics and therefore would require users who can explain what causes market fluctuations in general and why they apply to this specific case.
I think you should consult with Economics.SE instead and see if it is a question they could accept there.