Speculation is what damaged all 3 markets in terms of supply/demand balance, IMO. The .com boom/bust cycle coupled with Y2K fueled NASDAQ; housing speculation and ridiculous mortgages fueled the housing crisis, and the weak dollar and all the other markets tanking fueled (pardon the pun!) oil and the other commodities. From what I understand about commodities trading, oil has different rules than the other ones (grain, gold, etc.) and thus can be more volatile. But it's always the lower and middle classes that get squeezed in the middle.