Seeing as the popular press and countless "experts" continue to claim, whenever they get a chance, that the fortunes of alternative energy stocks are closely tied to the price of oil, I figured I would revisit the topic.
The graph below displays returns for all four ETFs, Oil, Nat Gas and the S&P 500 between Jan. 1, 2007 and Sep. 25, 2009 (click on the image for a large view).

This time around, I took a slightly different approach for my analysis: I correlated the weekly returns for US oil and US natural gas directly (as opposed to through an ETF) with returns for the S&P 500 and four alt energy ETFs. For US Oil and Nat Gas, I used price data provided by the Energy Information Administration here (Spot Price FOB Weighted by Estimated Export Volume) and here (Contract 1), respectively. I got ETF and S&P 500 price and index value data from Google Finance.
Read on Fossil & Alternative Energy: The Relationship That Isn't There