RAM is more like agricultural products (with short shelf-life) than commodities like fossil fuels, mineral ores, etc. You can manage an inventory or speculate on production, but you cannot really hold a "portfolio" of it in any sensible way.

So, you should get into RAM futures if you believe this is more than a transient arbitrage sort of situation. All extant RAM will become obsolete as the demand shifts to newer, fancier versions.