McD,
If the market crashes due to a oil Spike to $200 NZO will follow it down in the very short term but recover.
If the slope to $200 is a very slow and steady one, allowing companies to plan and react & its based mainly on supply/demand factors and the market finally crashes as non-oil/energy take a beating I think NZO will perform outstandlingly.
What happens next? A new set of market darlings which are energy based, both new and existing sources, R&D & food + land.
But that supposes the crash is not part of a worldwide economic meltdown reflecting the market crash which would errode oil demand & therefore prices.
I am of the opinion we may enter a period of oil price spikes, economic decline, demand errosion, price fall, economic recovery, price spike etc until there is a fundamental and permanent change i.e. peak oil irrefutably evident and permanent and/or the world economy learns to live with high prices.
Whatever happens I think NZO is a must have stock in any portfolio!,