Oil and related ETFs have experienced huge gains off its last year’s low, and energy companies have pocketed most of the change. However, the oil industry is expanding its options into other energy fields as it anticipates the eventual depletion of oil reserves.

Big western oil companies are trying to sustain reserves by expanding through acquisitions and investment, according to The Economist. For instance, Exxon Mobil (NYSE: XOM) estimated that exploration and capital spending hit $27.1 billion in 2009, or 4% higher than in 2008. The company also expects to continue spending around $25 billion to $30 billion a year over the next five years for the same purpose.

The population of the world is growing at a rapid pace. Billions of people require more of just about every imaginable natural resource — oil, gas, grains, livestock, metals, materials and water.

Most people believe it will be difficult, if not impossible, for suppliers to meet the needs of businesses or consumers. And yet, a bump on China’s Great Wall… a small movement in the direction of restricting money supply… has caused adverse ripples in the stock prices of companies working along the resources stream.

by Matt Hougan

If you’re looking for pie-in-the-sky ETF promises, Dave, you need look no further than your recent blog on the new Wildcat ETF. In case you missed it, it’s available here.